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Return the input as a numpy ndarray. This is a no-op if the input is already an ndarray. If the input is an adjusted_array, this extracts a read-only view of its internal data buffer. Parameters ---------- ndarray_or_adjusted_array : numpy.ndarray | zipline.data.adjusted_array Returns ------- out : The input, conve...
def ensure_ndarray(ndarray_or_adjusted_array): """ Return the input as a numpy ndarray. This is a no-op if the input is already an ndarray. If the input is an adjusted_array, this extracts a read-only view of its internal data buffer. Parameters ---------- ndarray_or_adjusted_array : nump...
Check that a window of length `window_length` is well-defined on `data`. Parameters ---------- data : np.ndarray[ndim=2] The array of data to check. window_length : int Length of the desired window. Returns ------- None Raises ------ WindowLengthNotPositive If window_length < 1. WindowLengthTooLong I...
def _check_window_params(data, window_length): """ Check that a window of length `window_length` is well-defined on `data`. Parameters ---------- data : np.ndarray[ndim=2] The array of data to check. window_length : int Length of the desired window. Returns ------- ...
Eq check with a short-circuit for identical objects.
def compare_arrays(left, right): "Eq check with a short-circuit for identical objects." return ( left is right or ((left.shape == right.shape) and (left == right).all()) )
LabelArray-aware implementation of np.where.
def labelarray_where(cond, trues, falses): """LabelArray-aware implementation of np.where. """ if trues.missing_value != falses.missing_value: raise ValueError( "Can't compute where on arrays with different missing values." ) strs = np.where(cond, trues.as_string_array(), fa...
Simple implementation of grouped row-wise function application. Parameters ---------- data : ndarray[ndim=2] Input array over which to apply a grouped function. group_labels : ndarray[ndim=2, dtype=int64] Labels to use to bucket inputs from array. Should be the same shape as array. func : function[ndarray[...
def naive_grouped_rowwise_apply(data, group_labels, func, func_args=(), out=None): """ Simple implementation of grouped row-wise function application. Parameters ---------- ...
Compute rowwise array quantiles on an input.
def quantiles(data, nbins_or_partition_bounds): """ Compute rowwise array quantiles on an input. """ return apply_along_axis( qcut, 1, data, q=nbins_or_partition_bounds, labels=False, )
A factory for decorators that restrict Term methods to only be callable on Terms with a specific dtype. This is conceptually similar to zipline.utils.input_validation.expect_dtypes, but provides more flexibility for providing error messages that are specifically targeting Term methods. Parameters ---------- dtype : n...
def restrict_to_dtype(dtype, message_template): """ A factory for decorators that restrict Term methods to only be callable on Terms with a specific dtype. This is conceptually similar to zipline.utils.input_validation.expect_dtypes, but provides more flexibility for providing error messages th...
Infer the domain from a collection of terms. The algorithm for inferring domains is as follows: - If all input terms have a domain of GENERIC, the result is GENERIC. - If there is exactly one non-generic domain in the input terms, the result is that domain. - Otherwise, an AmbiguousDomain error is raised. Parame...
def infer_domain(terms): """ Infer the domain from a collection of terms. The algorithm for inferring domains is as follows: - If all input terms have a domain of GENERIC, the result is GENERIC. - If there is exactly one non-generic domain in the input terms, the result is that domain. ...
Choose entries from ``dates`` to use for downsampling at ``frequency``. Parameters ---------- dates : pd.DatetimeIndex Dates from which to select sample choices. {frequency} Returns ------- indices : np.array[int64] An array condtaining indices of dates on which samples should be taken. The resulting ind...
def select_sampling_indices(dates, frequency): """ Choose entries from ``dates`` to use for downsampling at ``frequency``. Parameters ---------- dates : pd.DatetimeIndex Dates from which to select sample choices. {frequency} Returns ------- indices : np.array[int64] ...
The default implementation for ``populate_initial_workspace``. This function returns the ``initial_workspace`` argument without making any modifications. Parameters ---------- initial_workspace : dict[array-like] The initial workspace before we have populated it with any cached terms. root_mask_term : Term ...
def default_populate_initial_workspace(initial_workspace, root_mask_term, execution_plan, dates, assets): """The default implementation for ``populate_initial_w...
Create a MultiIndex for a pipeline output. Parameters ---------- dates : pd.DatetimeIndex Row labels for ``mask``. assets : pd.Index Column labels for ``mask``. mask : np.ndarray[bool] Mask array indicating date/asset pairs that should be included in output index. Returns ------- index : pd.MultiIndex...
def _pipeline_output_index(dates, assets, mask): """ Create a MultiIndex for a pipeline output. Parameters ---------- dates : pd.DatetimeIndex Row labels for ``mask``. assets : pd.Index Column labels for ``mask``. mask : np.ndarray[bool] Mask array indicating date/as...
Create a tuple containing all elements of tup, plus elem. Returns the new tuple and the index of elem in the new tuple.
def _ensure_element(tup, elem): """ Create a tuple containing all elements of tup, plus elem. Returns the new tuple and the index of elem in the new tuple. """ try: return tup, tup.index(elem) except ValueError: return tuple(chain(tup, (elem,))), len(tup)
Get the name of the Python magic method corresponding to `op`. Parameters ---------- op : str {'+','-','*', '/','**','&','|','^','<','<=','==','!=','>=','>'} The requested operation. commute : bool Whether to return the name of an equivalent method after flipping args. Returns ------- method_name : str Th...
def method_name_for_op(op, commute=False): """ Get the name of the Python magic method corresponding to `op`. Parameters ---------- op : str {'+','-','*', '/','**','&','|','^','<','<=','==','!=','>=','>'} The requested operation. commute : bool Whether to return the name of an e...
Specialize a term if it's loadable.
def maybe_specialize(term, domain): """Specialize a term if it's loadable. """ if isinstance(term, LoadableTerm): return term.specialize(domain) return term
Validate a `dtype` and `missing_value` passed to Term.__new__. Ensures that we know how to represent ``dtype``, and that missing_value is specified for types without default missing values. Returns ------- validated_dtype, validated_missing_value : np.dtype, any The dtype and missing_value to use for the new term...
def validate_dtype(termname, dtype, missing_value): """ Validate a `dtype` and `missing_value` passed to Term.__new__. Ensures that we know how to represent ``dtype``, and that missing_value is specified for types without default missing values. Returns ------- validated_dtype, validated_m...
Check that value is a valid categorical missing_value. Raises a TypeError if the value is cannot be used as the missing_value for a categorical_dtype Term.
def _assert_valid_categorical_missing_value(value): """ Check that value is a valid categorical missing_value. Raises a TypeError if the value is cannot be used as the missing_value for a categorical_dtype Term. """ label_types = LabelArray.SUPPORTED_SCALAR_TYPES if not isinstance(value, la...
Surround `content` with the first and last characters of `delimiters`. >>> delimit('[]', "foo") # doctest: +SKIP '[foo]' >>> delimit('""', "foo") # doctest: +SKIP '"foo"'
def delimit(delimiters, content): """ Surround `content` with the first and last characters of `delimiters`. >>> delimit('[]', "foo") # doctest: +SKIP '[foo]' >>> delimit('""', "foo") # doctest: +SKIP '"foo"' """ if len(delimiters) != 2: raise ValueError( "`delimit...
Get nodes from graph G with indegree 0
def roots(g): "Get nodes from graph G with indegree 0" return set(n for n, d in iteritems(g.in_degree()) if d == 0)
Draw `g` as a graph to `out`, in format `format`. Parameters ---------- g : zipline.pipeline.graph.TermGraph Graph to render. out : file-like object format_ : str {'png', 'svg'} Output format. include_asset_exists : bool Whether to filter out `AssetExists()` nodes.
def _render(g, out, format_, include_asset_exists=False): """ Draw `g` as a graph to `out`, in format `format`. Parameters ---------- g : zipline.pipeline.graph.TermGraph Graph to render. out : file-like object format_ : str {'png', 'svg'} Output format. include_asset_ex...
Display a TermGraph interactively from within IPython.
def display_graph(g, format='svg', include_asset_exists=False): """ Display a TermGraph interactively from within IPython. """ try: import IPython.display as display except ImportError: raise NoIPython("IPython is not installed. Can't display graph.") if format == 'svg': ...
Format key, value pairs from attrs into graphviz attrs format Examples -------- >>> format_attrs({'key1': 'value1', 'key2': 'value2'}) # doctest: +SKIP '[key1=value1, key2=value2]'
def format_attrs(attrs): """ Format key, value pairs from attrs into graphviz attrs format Examples -------- >>> format_attrs({'key1': 'value1', 'key2': 'value2'}) # doctest: +SKIP '[key1=value1, key2=value2]' """ if not attrs: return '' entries = ['='.join((key, value)) fo...
Build a weight vector for an exponentially-weighted statistic. The resulting ndarray is of the form:: [decay_rate ** length, ..., decay_rate ** 2, decay_rate] Parameters ---------- length : int The length of the desired weight vector. decay_rate : float The rate at which entries in the weight vector incr...
def exponential_weights(length, decay_rate): """ Build a weight vector for an exponentially-weighted statistic. The resulting ndarray is of the form:: [decay_rate ** length, ..., decay_rate ** 2, decay_rate] Parameters ---------- length : int The length of the desired weight v...
A decorator for methods whose signature is f(self, other) that coerces ``other`` to ``self.dtype``. This is used to make comparison operations between numbers and `Factor` instances work independently of whether the user supplies a float or integer literal. For example, if I write:: my_filter = my_factor > 3 my...
def coerce_numbers_to_my_dtype(f): """ A decorator for methods whose signature is f(self, other) that coerces ``other`` to ``self.dtype``. This is used to make comparison operations between numbers and `Factor` instances work independently of whether the user supplies a float or integer literal...
Compute the expected return dtype for the given binary operator. Parameters ---------- op : str Operator symbol, (e.g. '+', '-', ...). left : numpy.dtype Dtype of left hand side. right : numpy.dtype Dtype of right hand side. Returns ------- outdtype : numpy.dtype The dtype of the result of `left <op> ...
def binop_return_dtype(op, left, right): """ Compute the expected return dtype for the given binary operator. Parameters ---------- op : str Operator symbol, (e.g. '+', '-', ...). left : numpy.dtype Dtype of left hand side. right : numpy.dtype Dtype of right hand sid...
Factory function for making binary operator methods on a Factor subclass. Returns a function, "binary_operator" suitable for implementing functions like __add__.
def binary_operator(op): """ Factory function for making binary operator methods on a Factor subclass. Returns a function, "binary_operator" suitable for implementing functions like __add__. """ # When combining a Factor with a NumericalExpression, we use this # attrgetter instance to defer...
Factory function for making binary operator methods on a Factor. Returns a function, "reflected_binary_operator" suitable for implementing functions like __radd__.
def reflected_binary_operator(op): """ Factory function for making binary operator methods on a Factor. Returns a function, "reflected_binary_operator" suitable for implementing functions like __radd__. """ assert not is_comparison(op) @with_name(method_name_for_op(op, commute=True)) @...
Factory function for making unary operator methods for Factors.
def unary_operator(op): """ Factory function for making unary operator methods for Factors. """ # Only negate is currently supported. valid_ops = {'-'} if op not in valid_ops: raise ValueError("Invalid unary operator %s." % op) @with_doc("Unary Operator: '%s'" % op) @with_name(u...
Factory function for producing function application methods for Factor subclasses.
def function_application(func): """ Factory function for producing function application methods for Factor subclasses. """ if func not in NUMEXPR_MATH_FUNCS: raise ValueError("Unsupported mathematical function '%s'" % func) docstring = dedent( """\ Construct a Factor tha...
This implementation is based on scipy.stats.mstats.winsorize
def winsorize(row, min_percentile, max_percentile): """ This implementation is based on scipy.stats.mstats.winsorize """ a = row.copy() nan_count = isnan(row).sum() nonnan_count = a.size - nan_count # NOTE: argsort() sorts nans to the end of the array. idx = a.argsort() # Set value...
Compute slopes of linear regressions between columns of ``dependents`` and ``independent``. Parameters ---------- dependents : np.array[N, M] Array with columns of data to be regressed against ``independent``. independent : np.array[N, 1] Independent variable of the regression allowed_missing : int Number ...
def vectorized_beta(dependents, independent, allowed_missing, out=None): """ Compute slopes of linear regressions between columns of ``dependents`` and ``independent``. Parameters ---------- dependents : np.array[N, M] Array with columns of data to be regressed against ``independent``. ...
Compute Pearson's r between columns of ``dependents`` and ``independents``. Parameters ---------- dependents : np.array[N, M] Array with columns of data to be regressed against ``independent``. independents : np.array[N, M] or np.array[N, 1] Independent variable(s) of the regression. If a single column is ...
def vectorized_pearson_r(dependents, independents, allowed_missing, out=None): """ Compute Pearson's r between columns of ``dependents`` and ``independents``. Parameters ---------- dependents : np.array[N, M] Array with columns of data to be regressed against ``independent``. independen...
Concatenate a sequence of tuples into one tuple.
def concat_tuples(*tuples): """ Concatenate a sequence of tuples into one tuple. """ return tuple(chain(*tuples))
Factory function for making binary operator methods on a Filter subclass. Returns a function "binary_operator" suitable for implementing functions like __and__ or __or__.
def binary_operator(op): """ Factory function for making binary operator methods on a Filter subclass. Returns a function "binary_operator" suitable for implementing functions like __and__ or __or__. """ # When combining a Filter with a NumericalExpression, we use this # attrgetter instance...
Factory function for making unary operator methods for Filters.
def unary_operator(op): """ Factory function for making unary operator methods for Filters. """ valid_ops = {'~'} if op not in valid_ops: raise ValueError("Invalid unary operator %s." % op) def unary_operator(self): # This can't be hoisted up a scope because the types returned b...
Factory function for making DelegatingHooks methods.
def delegating_hooks_method(method_name): """Factory function for making DelegatingHooks methods. """ if method_name in PIPELINE_HOOKS_CONTEXT_MANAGERS: # Generate a contextmanager that enters the context of all child hooks. @wraps(getattr(PipelineHooks, method_name)) @contextmanager...
Wrapper for contextlib.contextmanager that tracks which methods of PipelineHooks are contextmanagers in CONTEXT_MANAGER_METHODS.
def contextmanager(f): """ Wrapper for contextlib.contextmanager that tracks which methods of PipelineHooks are contextmanagers in CONTEXT_MANAGER_METHODS. """ PIPELINE_HOOKS_CONTEXT_MANAGERS.add(f.__name__) return _contextmanager(f)
Repr a value and html-escape the result. If an error is thrown by the repr, show a placeholder.
def repr_htmlsafe(t): """Repr a value and html-escape the result. If an error is thrown by the repr, show a placeholder. """ try: r = repr(t) except Exception: r = "(Error Displaying {})".format(type(t).__name__) return escape_html(str(r), quote=True)
Factory function for making testing methods.
def testing_hooks_method(method_name): """Factory function for making testing methods. """ if method_name in PIPELINE_HOOKS_CONTEXT_MANAGERS: # Generate a method that enters the context of all sub-hooks. @wraps(getattr(PipelineHooks, method_name)) @contextmanager def ctx(self...
Compute the set of resource columns required to serve `columns`.
def required_estimates_fields(columns): """ Compute the set of resource columns required to serve `columns`. """ # We also expect any of the field names that our loadable columns # are mapped to. return metadata_columns.union(viewvalues(columns))
Verify that the columns of ``events`` can be used by a EarningsEstimatesLoader to serve the BoundColumns described by `columns`.
def validate_column_specs(events, columns): """ Verify that the columns of ``events`` can be used by a EarningsEstimatesLoader to serve the BoundColumns described by `columns`. """ required = required_estimates_fields(columns) received = set(events.columns) missing = required - received ...
Compute the set of resource columns required to serve ``next_value_columns`` and ``previous_value_columns``.
def required_event_fields(next_value_columns, previous_value_columns): """ Compute the set of resource columns required to serve ``next_value_columns`` and ``previous_value_columns``. """ # These metadata columns are used to align event indexers. return { TS_FIELD_NAME, SID_FIELD...
Verify that the columns of ``events`` can be used by an EventsLoader to serve the BoundColumns described by ``next_value_columns`` and ``previous_value_columns``.
def validate_column_specs(events, next_value_columns, previous_value_columns): """ Verify that the columns of ``events`` can be used by an EventsLoader to serve the BoundColumns described by ``next_value_columns`` and ``previous_value_columns``. """ required = required_event_fields(next_value_co...
For a given asset/date/column combination, we generate a corresponding raw value using the following formula for OHLCV columns: data(asset, date, column) = (100,000 * asset_id) + (10,000 * column_num) + (date - Jan 1 2000).days # ~6000 for 2015 where: column_num...
def make_bar_data(asset_info, calendar, holes=None): """ For a given asset/date/column combination, we generate a corresponding raw value using the following formula for OHLCV columns: data(asset, date, column) = (100,000 * asset_id) + (10,000 * column_num) ...
Check that the raw value for an asset/date/column triple is as expected. Used by tests to verify data written by a writer.
def expected_bar_value(asset_id, date, colname): """ Check that the raw value for an asset/date/column triple is as expected. Used by tests to verify data written by a writer. """ from_asset = asset_id * 100000 from_colname = OHLCV.index(colname) * 1000 from_date = (date - PSEUDO_EPOCH)...
Return an 2D array containing cls.expected_value(asset_id, date, colname) for each date/asset pair in the inputs. Missing locs are filled with 0 for volume and NaN for price columns: - Values before/after an asset's lifetime. - Values for asset_ids not contained in asset_info. - Locs defined in `holes`.
def expected_bar_values_2d(dates, assets, asset_info, colname, holes=None): """ Return an 2D array containing cls.expected_value(asset_id, date, colname) for each date/asset pair in the inputs. M...
Make a PipelineLoader that emits np.eye arrays for the columns in ``TestingDataSet``.
def make_eye_loader(dates, sids): """ Make a PipelineLoader that emits np.eye arrays for the columns in ``TestingDataSet``. """ return EyeLoader(TestingDataSet.columns, dates, sids)
Make a PipelineLoader that emits random arrays seeded with `seed` for the columns in ``TestingDataSet``.
def make_seeded_random_loader(seed, dates, sids, columns=TestingDataSet.columns): """ Make a PipelineLoader that emits random arrays seeded with `seed` for the columns in ``TestingDataSet``. """ return SeededRa...
Check if a numpy array is sorted.
def is_sorted_ascending(a): """Check if a numpy array is sorted.""" return (np.fmax.accumulate(a) <= a).all()
Construct an index array that, when applied to an array of values, produces a 2D array containing the values associated with the next event for each sid at each moment in time. Locations where no next event was known will be filled with -1. Parameters ---------- all_dates : ndarray[datetime64[ns], ndim=1] Row lab...
def next_event_indexer(all_dates, data_query_cutoff, all_sids, event_dates, event_timestamps, event_sids): """ Construct an index array that, when applied to an array of values, produces a 2D a...
Construct an index array that, when applied to an array of values, produces a 2D array containing the values associated with the previous event for each sid at each moment in time. Locations where no previous event was known will be filled with -1. Parameters ---------- data_query_cutoff : pd.DatetimeIndex The bo...
def previous_event_indexer(data_query_cutoff_times, all_sids, event_dates, event_timestamps, event_sids): """ Construct an index array that, when applied to an array of values, produces a 2D array con...
Determine the last piece of information known on each date in the date index for each group. Input df MUST be sorted such that the correct last item is chosen from each group. Parameters ---------- df : pd.DataFrame The DataFrame containing the data to be grouped. Must be sorted so that the correct last item ...
def last_in_date_group(df, data_query_cutoff_times, assets, reindex=True, have_sids=True, extra_groupers=None): """ Determine the last piece of information known on each date in the date index...
Forward fill values in a DataFrame with special logic to handle cases that pd.DataFrame.ffill cannot and cast columns to appropriate types. Parameters ---------- df : pd.DataFrame The DataFrame to do forward-filling on. columns : list of BoundColumn The BoundColumns that correspond to columns in the DataFrame ...
def ffill_across_cols(df, columns, name_map): """ Forward fill values in a DataFrame with special logic to handle cases that pd.DataFrame.ffill cannot and cast columns to appropriate types. Parameters ---------- df : pd.DataFrame The DataFrame to do forward-filling on. columns : lis...
Shift dates of a pipeline query back by ``shift`` days. Parameters ---------- dates : DatetimeIndex All known dates. start_date : pd.Timestamp Start date of the pipeline query. end_date : pd.Timestamp End date of the pipeline query. shift : int The number of days to shift back the query dates. Returns...
def shift_dates(dates, start_date, end_date, shift): """ Shift dates of a pipeline query back by ``shift`` days. Parameters ---------- dates : DatetimeIndex All known dates. start_date : pd.Timestamp Start date of the pipeline query. end_date : pd.Timestamp End date ...
Given a datashape type, return the associated numpy type. Maps datashape's DateTime type to numpy's `datetime64[ns]` dtype, since the numpy datetime returned by datashape isn't supported by pipeline. Parameters ---------- type_: datashape.coretypes.Type The datashape type. Returns ------- type_ np.dtype The n...
def datashape_type_to_numpy(type_): """ Given a datashape type, return the associated numpy type. Maps datashape's DateTime type to numpy's `datetime64[ns]` dtype, since the numpy datetime returned by datashape isn't supported by pipeline. Parameters ---------- type_: datashape.coretypes.Ty...
Creates or returns a dataset from a blaze expression. Parameters ---------- expr : Expr The blaze expression representing the values. missing_values : frozenset((name, value) pairs Association pairs column name and missing_value for that column. This needs to be a frozenset rather than a dict or tuple of ...
def new_dataset(expr, missing_values, domain): """ Creates or returns a dataset from a blaze expression. Parameters ---------- expr : Expr The blaze expression representing the values. missing_values : frozenset((name, value) pairs Association pairs column name and missing_value...
Validate that the expression and resources passed match up. Parameters ---------- name : str The name of the argument we are checking. expr : Expr The potentially bound expr. resources The explicitly passed resources to compute expr. Raises ------ ValueError If the resources do not match for an expres...
def _check_resources(name, expr, resources): """Validate that the expression and resources passed match up. Parameters ---------- name : str The name of the argument we are checking. expr : Expr The potentially bound expr. resources The explicitly passed resources to com...
Check that a field is a datetime inside some measure. Parameters ---------- name : str The name of the field to check. measure : Record The record to check the field of. Raises ------ TypeError If the field is not a datetime inside ``measure``.
def _check_datetime_field(name, measure): """Check that a field is a datetime inside some measure. Parameters ---------- name : str The name of the field to check. measure : Record The record to check the field of. Raises ------ TypeError If the field is not a d...
Find the correct metadata expression for the expression. Parameters ---------- field : {'deltas', 'checkpoints'} The kind of metadata expr to lookup. expr : Expr The baseline expression. metadata_expr : Expr, 'auto', or None The metadata argument. If this is 'auto', then the metadata table will be sear...
def _get_metadata(field, expr, metadata_expr, no_metadata_rule): """Find the correct metadata expression for the expression. Parameters ---------- field : {'deltas', 'checkpoints'} The kind of metadata expr to lookup. expr : Expr The baseline expression. metadata_expr : Expr, 'a...
Duplicate the asof_date column as the timestamp column. Parameters ---------- expr : Expr or None The expression to change the columns of. Returns ------- transformed : Expr or None The transformed expression or None if ``expr`` is None.
def _ad_as_ts(expr): """Duplicate the asof_date column as the timestamp column. Parameters ---------- expr : Expr or None The expression to change the columns of. Returns ------- transformed : Expr or None The transformed expression or None if ``expr`` is None. """ ...
Verify that the baseline and deltas expressions have a timestamp field. If there is not a ``TS_FIELD_NAME`` on either of the expressions, it will be copied from the ``AD_FIELD_NAME``. If one is provided, then we will verify that it is the correct dshape. Parameters ---------- dataset_expr : Expr The baseline expr...
def _ensure_timestamp_field(dataset_expr, deltas, checkpoints): """Verify that the baseline and deltas expressions have a timestamp field. If there is not a ``TS_FIELD_NAME`` on either of the expressions, it will be copied from the ``AD_FIELD_NAME``. If one is provided, then we will verify that it is t...
Create a Pipeline API object from a blaze expression. Parameters ---------- expr : Expr The blaze expression to use. deltas : Expr, 'auto' or None, optional The expression to use for the point in time adjustments. If the string 'auto' is passed, a deltas expr will be looked up by stepping up the expres...
def from_blaze(expr, deltas='auto', checkpoints='auto', loader=None, resources=None, odo_kwargs=None, missing_values=None, domain=GENERIC, no_deltas_rule='warn', no_checkpoints_rule='wa...
Bind a Blaze expression to resources. Parameters ---------- expr : bz.Expr The expression to which we want to bind resources. resources : dict[bz.Symbol -> any] Mapping from the loadable terms of ``expr`` to actual data resources. Returns ------- bound_expr : bz.Expr ``expr`` with bound resources.
def bind_expression_to_resources(expr, resources): """ Bind a Blaze expression to resources. Parameters ---------- expr : bz.Expr The expression to which we want to bind resources. resources : dict[bz.Symbol -> any] Mapping from the loadable terms of ``expr`` to actual data reso...
Computes a lower bound and a DataFrame checkpoints. Parameters ---------- checkpoints : Expr Bound blaze expression for a checkpoints table from which to get a computed lower bound. colnames : iterable of str The names of the columns for which checkpoints should be computed. lower_dt : pd.Timestamp The...
def get_materialized_checkpoints(checkpoints, colnames, lower_dt, odo_kwargs): """ Computes a lower bound and a DataFrame checkpoints. Parameters ---------- checkpoints : Expr Bound blaze expression for a checkpoints table from which to get a computed lower bound. colnames : ite...
Query a blaze expression in a given time range properly forward filling from values that fall before the lower date. Parameters ---------- expr : Expr Bound blaze expression. lower : datetime The lower date to query for. upper : datetime The upper date to query for. checkpoints : Expr, optional Bound b...
def ffill_query_in_range(expr, lower, upper, checkpoints=None, odo_kwargs=None, ts_field=TS_FIELD_NAME): """Query a blaze expression in a given time range properly forward filling from va...
Given an expression representing data to load, perform normalization and forward-filling and return the data, materialized. Only accepts data with a `sid` field. Parameters ---------- assets : pd.int64index the assets to load data for. data_query_cutoff_times : pd.DatetimeIndex The datetime when data should no...
def load_raw_data(assets, data_query_cutoff_times, expr, odo_kwargs, checkpoints=None): """ Given an expression representing data to load, perform normalization and forward-filling and return the data, materialized. Only accepts data wi...
Utility to generate a stream of dates.
def date_gen(start, end, trading_calendar, delta=timedelta(minutes=1), repeats=None): """ Utility to generate a stream of dates. """ daily_delta = not (delta.total_seconds() % timedelta(days=1).total_seconds()) cur = start ...
Convert a string in US/Eastern time to UTC
def to_utc(time_str): """Convert a string in US/Eastern time to UTC""" return pd.Timestamp(time_str, tz='US/Eastern').tz_convert('UTC')
Convert a pandas-intelligible string to (integer) seconds since UTC. >>> from pandas import Timestamp >>> (Timestamp('2014-01-01') - Timestamp(0)).total_seconds() 1388534400.0 >>> str_to_seconds('2014-01-01') 1388534400
def str_to_seconds(s): """ Convert a pandas-intelligible string to (integer) seconds since UTC. >>> from pandas import Timestamp >>> (Timestamp('2014-01-01') - Timestamp(0)).total_seconds() 1388534400.0 >>> str_to_seconds('2014-01-01') 1388534400 """ return timedelta_to_integral_sec...
Return an iterator of all pairs, (v0, v1) from values such that `pred(v0, v1) == True` Parameters ---------- values : iterable pred : function Returns ------- pairs_iterator : generator Generator yielding pairs matching `pred`. Examples -------- >>> from zipline.testing import all_pairs_matching_predicate >>> fr...
def all_pairs_matching_predicate(values, pred): """ Return an iterator of all pairs, (v0, v1) from values such that `pred(v0, v1) == True` Parameters ---------- values : iterable pred : function Returns ------- pairs_iterator : generator Generator yielding pairs matchin...
Return an iterator over pairs, (v0, v1), drawn from values. If `include_diagonal` is True, returns all pairs such that v0 <= v1. If `include_diagonal` is False, returns all pairs such that v0 < v1.
def product_upper_triangle(values, include_diagonal=False): """ Return an iterator over pairs, (v0, v1), drawn from values. If `include_diagonal` is True, returns all pairs such that v0 <= v1. If `include_diagonal` is False, returns all pairs such that v0 < v1. """ return all_pairs_matching_pre...
Return all valid sub-indices of a pandas Index.
def all_subindices(index): """ Return all valid sub-indices of a pandas Index. """ return ( index[start:stop] for start, stop in product_upper_triangle(range(len(index) + 1)) )
Construct an iterable of length-1 strings beginning with `start` and ending with `stop`. Parameters ---------- start : str The first character. stop : str The last character. Returns ------- chars: iterable[str] Iterable of strings beginning with start and ending with stop. Examples -------- >>> chrange(...
def chrange(start, stop): """ Construct an iterable of length-1 strings beginning with `start` and ending with `stop`. Parameters ---------- start : str The first character. stop : str The last character. Returns ------- chars: iterable[str] Iterable of ...
Convert the asset info dataframe into a dataframe of trade data for each sid, and write to the writer if provided. Write NaNs for locations where assets did not exist. Return a dict of the dataframes, keyed by sid.
def make_trade_data_for_asset_info(dates, asset_info, price_start, price_step_by_date, price_step_by_sid, volume_start, ...
Wrapper around np.testing.assert_allclose that also verifies that inputs are ndarrays. See Also -------- np.assert_allclose
def check_allclose(actual, desired, rtol=1e-07, atol=0, err_msg='', verbose=True): """ Wrapper around np.testing.assert_allclose that also verifies that inputs are ndarrays. See Also -------- np.asser...
Wrapper around np.testing.assert_array_equal that also verifies that inputs are ndarrays. See Also -------- np.assert_array_equal
def check_arrays(x, y, err_msg='', verbose=True, check_dtypes=True): """ Wrapper around np.testing.assert_array_equal that also verifies that inputs are ndarrays. See Also -------- np.assert_array_equal """ assert type(x) == type(y), "{x} != {y}".format(x=type(x), y=type(y)) assert ...
Context manager for creating an empty assets db. See Also -------- tmp_assets_db
def empty_assets_db(): """Context manager for creating an empty assets db. See Also -------- tmp_assets_db """ return tmp_assets_db(equities=None)
Context manager for creating an empty asset finder. See Also -------- empty_assets_db tmp_assets_db tmp_asset_finder
def empty_asset_finder(): """Context manager for creating an empty asset finder. See Also -------- empty_assets_db tmp_assets_db tmp_asset_finder """ return tmp_asset_finder(equities=None)
Construct a subtest in a unittest. Consider using ``zipline.testing.parameter_space`` when subtests are constructed over a single input or over the cross-product of multiple inputs. ``subtest`` works by decorating a function as a subtest. The decorated function will be run by iterating over the ``iterator`` and *unpa...
def subtest(iterator, *_names): """ Construct a subtest in a unittest. Consider using ``zipline.testing.parameter_space`` when subtests are constructed over a single input or over the cross-product of multiple inputs. ``subtest`` works by decorating a function as a subtest. The decorated f...
Assert that two pandas Timestamp objects are the same. Parameters ---------- left, right : pd.Timestamp The values to compare. compare_nat_equal : bool, optional Whether to consider `NaT` values equal. Defaults to True. msg : str, optional A message to forward to `pd.util.testing.assert_equal`.
def assert_timestamp_equal(left, right, compare_nat_equal=True, msg=""): """ Assert that two pandas Timestamp objects are the same. Parameters ---------- left, right : pd.Timestamp The values to compare. compare_nat_equal : bool, optional Whether to consider `NaT` values equal. ...
Return the power set (i.e., the set of all subsets) of entries in `values`.
def powerset(values): """ Return the power set (i.e., the set of all subsets) of entries in `values`. """ return concat(combinations(values, i) for i in range(len(values) + 1))
Helper for converting a dict of strings to a Series of datetimes. This is just for making the test cases more readable.
def to_series(knowledge_dates, earning_dates): """ Helper for converting a dict of strings to a Series of datetimes. This is just for making the test cases more readable. """ return pd.Series( index=pd.to_datetime(knowledge_dates), data=pd.to_datetime(earning_dates), )
Generate calendars to use as inputs.
def gen_calendars(start, stop, critical_dates): """ Generate calendars to use as inputs. """ all_dates = pd.date_range(start, stop, tz='utc') for to_drop in map(list, powerset(critical_dates)): # Have to yield tuples. yield (all_dates.drop(to_drop),) # Also test with the trading...
A contextManager that yields a SimplePipelineEngine holding a reference to an AssetFinder generated via tmp_asset_finder. Parameters ---------- calendar : pd.DatetimeIndex Calendar to pass to the constructed PipelineEngine. sids : iterable[int] Sids to use for the temp asset finder. random_seed : int Integ...
def temp_pipeline_engine(calendar, sids, random_seed, symbols=None): """ A contextManager that yields a SimplePipelineEngine holding a reference to an AssetFinder generated via tmp_asset_finder. Parameters ---------- calendar : pd.DatetimeIndex Calendar to pass to the constructed Pipeli...
Get a boolean value from the environment, making a reasonable attempt to convert "truthy" values to True and "falsey" values to False. Strings are coerced to bools using ``json.loads(s.lower())``. Parameters ---------- name : str Name of the environment variable. default : bool, optional Value to use if the e...
def bool_from_envvar(name, default=False, env=None): """ Get a boolean value from the environment, making a reasonable attempt to convert "truthy" values to True and "falsey" values to False. Strings are coerced to bools using ``json.loads(s.lower())``. Parameters ---------- name : str ...
Wrapper around subtest that allows passing keywords mapping names to iterables of values. The decorated test function will be called with the cross-product of all possible inputs Examples -------- >>> from unittest import TestCase >>> class SomeTestCase(TestCase): ... @parameter_space(x=[1, 2], y=[2, 3]) ... ...
def parameter_space(__fail_fast=_FAIL_FAST_DEFAULT, **params): """ Wrapper around subtest that allows passing keywords mapping names to iterables of values. The decorated test function will be called with the cross-product of all possible inputs Examples -------- >>> from unittest impo...
Create a 2D numpy array with the given shape containing alternating values of False, True, False, True,... along each row and each column. Examples -------- >>> make_alternating_boolean_array((4,4)) array([[ True, False, True, False], [False, True, False, True], [ True, False, True, False], [F...
def make_alternating_boolean_array(shape, first_value=True): """ Create a 2D numpy array with the given shape containing alternating values of False, True, False, True,... along each row and each column. Examples -------- >>> make_alternating_boolean_array((4,4)) array([[ True, False, True...
Create a numpy array with the given shape containing cascading boolean values, with `first_value` being the top-left value. Examples -------- >>> make_cascading_boolean_array((4,4)) array([[ True, True, True, False], [ True, True, False, False], [ True, False, False, False], [False, False, Fals...
def make_cascading_boolean_array(shape, first_value=True): """ Create a numpy array with the given shape containing cascading boolean values, with `first_value` being the top-left value. Examples -------- >>> make_cascading_boolean_array((4,4)) array([[ True, True, True, False], ...
Shuffle each row in ``array`` based on permutations generated by ``seed``. Parameters ---------- seed : int Seed for numpy.RandomState array : np.ndarray[ndim=2] Array over which to apply permutations.
def permute_rows(seed, array): """ Shuffle each row in ``array`` based on permutations generated by ``seed``. Parameters ---------- seed : int Seed for numpy.RandomState array : np.ndarray[ndim=2] Array over which to apply permutations. """ rand = np.random.RandomState(s...
Returns a TestHandler which will be used by the given testcase. This handler can be used to test log messages. Parameters ---------- testcase: unittest.TestCase The test class in which the log handler will be used. *args, **kwargs Forwarded to the new TestHandler object. Returns ------- handler: logbook.TestH...
def make_test_handler(testcase, *args, **kwargs): """ Returns a TestHandler which will be used by the given testcase. This handler can be used to test log messages. Parameters ---------- testcase: unittest.TestCase The test class in which the log handler will be used. *args, **kwarg...
Write a compressed (gzipped) file to `path`.
def write_compressed(path, content): """ Write a compressed (gzipped) file to `path`. """ with gzip.open(path, 'wb') as f: f.write(content)
Write a compressed (gzipped) file from `path`.
def read_compressed(path): """ Write a compressed (gzipped) file from `path`. """ with gzip.open(path, 'rb') as f: return f.read()
Context manager for patching the operating system environment.
def patch_os_environment(remove=None, **values): """ Context manager for patching the operating system environment. """ old_values = {} remove = remove or [] for key in remove: old_values[key] = os.environ.pop(key) for key, value in values.iteritems(): old_values[key] = os.g...
Patch pandas.read_csv to map lookups from url to another. Parameters ---------- url_map : mapping[str or file-like object -> str or file-like object] The mapping to use to redirect read_csv calls. module : module, optional The module to patch ``read_csv`` on. By default this is ``pandas``. This should be s...
def patch_read_csv(url_map, module=pd, strict=False): """Patch pandas.read_csv to map lookups from url to another. Parameters ---------- url_map : mapping[str or file-like object -> str or file-like object] The mapping to use to redirect read_csv calls. module : module, optional The...
Ensure that an object gets doctested. This is useful for instances of objects like curry or partial which are not discovered by default. Parameters ---------- f : any The thing to doctest. name : str, optional The name to use in the doctest function mapping. If this is None, Then ``f.__name__`` will be use...
def ensure_doctest(f, name=None): """Ensure that an object gets doctested. This is useful for instances of objects like curry or partial which are not discovered by default. Parameters ---------- f : any The thing to doctest. name : str, optional The name to use in the doctest f...
Construct the time series of prices that produce the given returns. Parameters ---------- returns : np.ndarray[float] The returns that these prices generate. starting_price : float The value of the asset. Returns ------- prices : np.ndaray[float] The prices that generate the given returns. This array will...
def prices_generating_returns(returns, starting_price): """Construct the time series of prices that produce the given returns. Parameters ---------- returns : np.ndarray[float] The returns that these prices generate. starting_price : float The value of the asset. Returns --...
Construct a time series of prices that ticks by a random multiple of ``tick_size`` every period. Parameters ---------- starting_price : float The first price of the series. count : int Number of price observations to return. tick_size : float Unit of price movement between observations. tick_range : (int, ...
def random_tick_prices(starting_price, count, tick_size=0.01, tick_range=(-5, 7), seed=42): """ Construct a time series of prices that ticks by a random multiple of ``tick_size`` every period. Parameters ---...
Generate a random walk of minute returns which meets the given OHLCV profile for an asset. The volume will be evenly distributed through the day. Parameters ---------- open_ : float The day's open. high : float The day's high. low : float The day's low. close : float The day's close. volume : float ...
def simulate_minutes_for_day(open_, high, low, close, volume, trading_minutes=390, random_state=None): """Generate a random walk of minute ret...
Create a new pipeline domain with a simple date_range index.
def create_simple_domain(start, end, country_code): """Create a new pipeline domain with a simple date_range index. """ return EquitySessionDomain(pd.date_range(start, end), country_code)
Write an HDF5 file of pricing data using an HDF5DailyBarWriter.
def write_hdf5_daily_bars(writer, asset_finder, country_codes, generate_data, generate_currency_codes): """Write an HDF5 file of pricing data using an HDF5DailyBarWriter. """ asset_finder = asset_finder ...
Build an exchange_info suitable for passing to an AssetFinder from a list of EquityCalendarDomain.
def exchange_info_for_domains(domains): """ Build an exchange_info suitable for passing to an AssetFinder from a list of EquityCalendarDomain. """ return pd.DataFrame.from_records([ {'exchange': domain.calendar.name, 'country_code': domain.country_code} for domain in domains ])