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|
|
| """If there is one recurring theme in ``boltons``, it is that Python |
| has excellent datastructures that constitute a good foundation for |
| most quick manipulations, as well as building applications. However, |
| Python usage has grown much faster than builtin data structure |
| power. Python has a growing need for more advanced general-purpose |
| data structures which behave intuitively. |
| |
| The :class:`Table` class is one example. When handed one- or |
| two-dimensional data, it can provide useful, if basic, text and HTML |
| renditions of small to medium sized data. It also heuristically |
| handles recursive data of various formats (lists, dicts, namedtuples, |
| objects). |
| |
| For more advanced :class:`Table`-style manipulation check out the |
| `pandas`_ DataFrame. |
| |
| .. _pandas: http://pandas.pydata.org/ |
| |
| """ |
|
|
|
|
| from html import escape as html_escape |
| import types |
| from itertools import islice |
| from collections.abc import Sequence, Mapping, MutableSequence |
|
|
| try: |
| from .typeutils import make_sentinel |
| _MISSING = make_sentinel(var_name='_MISSING') |
| except ImportError: |
| _MISSING = object() |
|
|
| """ |
| Some idle feature thoughts: |
| |
| * shift around column order without rearranging data |
| * gotta make it so you can add additional items, not just initialize with |
| * maybe a shortcut would be to allow adding of Tables to other Tables |
| * what's the perf of preallocating lists and overwriting items versus |
| starting from empty? |
| * is it possible to effectively tell the difference between when a |
| Table is from_data()'d with a single row (list) or with a list of lists? |
| * CSS: white-space pre-line or pre-wrap maybe? |
| * Would be nice to support different backends (currently uses lists |
| exclusively). Sometimes large datasets come in list-of-dicts and |
| list-of-tuples format and it's desirable to cut down processing overhead. |
| |
| TODO: make iterable on rows? |
| """ |
|
|
| __all__ = ['Table'] |
|
|
|
|
| def to_text(obj, maxlen=None): |
| try: |
| text = str(obj) |
| except Exception: |
| try: |
| text = str(repr(obj)) |
| except Exception: |
| text = str(object.__repr__(obj)) |
| if maxlen and len(text) > maxlen: |
| text = text[:maxlen - 3] + '...' |
| |
| return text |
|
|
|
|
| def escape_html(obj, maxlen=None): |
| text = to_text(obj, maxlen=maxlen) |
| return html_escape(text, quote=True) |
|
|
|
|
| _DNR = {type(None), bool, complex, float, type(NotImplemented), slice, |
| str, bytes, int, |
| types.FunctionType, types.MethodType, |
| types.BuiltinFunctionType, types.GeneratorType} |
|
|
|
|
| class UnsupportedData(TypeError): |
| pass |
|
|
|
|
| class InputType: |
| def __init__(self, *a, **kw): |
| pass |
|
|
| def get_entry_seq(self, data_seq, headers): |
| return [self.get_entry(entry, headers) for entry in data_seq] |
|
|
|
|
| class DictInputType(InputType): |
| def check_type(self, obj): |
| return isinstance(obj, Mapping) |
|
|
| def guess_headers(self, obj): |
| return sorted(obj.keys()) |
|
|
| def get_entry(self, obj, headers): |
| return [obj.get(h) for h in headers] |
|
|
| def get_entry_seq(self, obj, headers): |
| return [[ci.get(h) for h in headers] for ci in obj] |
|
|
|
|
| class ObjectInputType(InputType): |
| def check_type(self, obj): |
| return type(obj) not in _DNR and hasattr(obj, '__class__') |
|
|
| def guess_headers(self, obj): |
| headers = [] |
| for attr in dir(obj): |
| |
| try: |
| val = getattr(obj, attr) |
| except Exception: |
| |
| |
| continue |
| if callable(val): |
| continue |
| headers.append(attr) |
| return headers |
|
|
| def get_entry(self, obj, headers): |
| values = [] |
| for h in headers: |
| try: |
| values.append(getattr(obj, h)) |
| except Exception: |
| values.append(None) |
| return values |
|
|
|
|
| |
| |
| |
| class ListInputType(InputType): |
| def check_type(self, obj): |
| return isinstance(obj, MutableSequence) |
|
|
| def guess_headers(self, obj): |
| return None |
|
|
| def get_entry(self, obj, headers): |
| return obj |
|
|
| def get_entry_seq(self, obj_seq, headers): |
| return obj_seq |
|
|
|
|
| class TupleInputType(InputType): |
| def check_type(self, obj): |
| return isinstance(obj, tuple) |
|
|
| def guess_headers(self, obj): |
| return None |
|
|
| def get_entry(self, obj, headers): |
| return list(obj) |
|
|
| def get_entry_seq(self, obj_seq, headers): |
| return [list(t) for t in obj_seq] |
|
|
|
|
| class NamedTupleInputType(InputType): |
| def check_type(self, obj): |
| return hasattr(obj, '_fields') and isinstance(obj, tuple) |
|
|
| def guess_headers(self, obj): |
| return list(obj._fields) |
|
|
| def get_entry(self, obj, headers): |
| return [getattr(obj, h, None) for h in headers] |
|
|
| def get_entry_seq(self, obj_seq, headers): |
| return [[getattr(obj, h, None) for h in headers] for obj in obj_seq] |
|
|
|
|
| class Table: |
| """ |
| This Table class is meant to be simple, low-overhead, and extensible. Its |
| most common use would be for translation between in-memory data |
| structures and serialization formats, such as HTML and console-ready text. |
| |
| As such, it stores data in list-of-lists format, and *does not* copy |
| lists passed in. It also reserves the right to modify those lists in a |
| "filling" process, whereby short lists are extended to the width of |
| the table (usually determined by number of headers). This greatly |
| reduces overhead and processing/validation that would have to occur |
| otherwise. |
| |
| General description of headers behavior: |
| |
| Headers describe the columns, but are not part of the data, however, |
| if the *headers* argument is omitted, Table tries to infer header |
| names from the data. It is possible to have a table with no headers, |
| just pass in ``headers=None``. |
| |
| Supported inputs: |
| |
| * :class:`list` of :class:`list` objects |
| * :class:`dict` (list/single) |
| * :class:`object` (list/single) |
| * :class:`collections.namedtuple` (list/single) |
| * TODO: DB API cursor? |
| * TODO: json |
| |
| Supported outputs: |
| |
| * HTML |
| * Pretty text (also usable as GF Markdown) |
| * TODO: CSV |
| * TODO: json |
| * TODO: json lines |
| |
| To minimize resident size, the Table data is stored as a list of lists. |
| """ |
|
|
| |
| _input_types = [DictInputType(), ListInputType(), |
| NamedTupleInputType(), TupleInputType(), |
| ObjectInputType()] |
|
|
| _html_tr, _html_tr_close = '<tr>', '</tr>' |
| _html_th, _html_th_close = '<th>', '</th>' |
| _html_td, _html_td_close = '<td>', '</td>' |
| _html_thead, _html_thead_close = '<thead>', '</thead>' |
| _html_tbody, _html_tbody_close = '<tbody>', '</tbody>' |
|
|
| |
| _html_table_tag, _html_table_tag_close = '<table>', '</table>' |
|
|
| def __init__(self, data=None, headers=_MISSING, metadata=None): |
| if headers is _MISSING: |
| headers = [] |
| if data: |
| headers, data = list(data[0]), islice(data, 1, None) |
| self.headers = headers or [] |
| self.metadata = metadata or {} |
| self._data = [] |
| self._width = 0 |
|
|
| self.extend(data) |
|
|
| def extend(self, data): |
| """ |
| Append the given data to the end of the Table. |
| """ |
| if not data: |
| return |
| self._data.extend(data) |
| self._set_width() |
| self._fill() |
|
|
| def _set_width(self, reset=False): |
| if reset: |
| self._width = 0 |
| if self._width: |
| return |
| if self.headers: |
| self._width = len(self.headers) |
| return |
| self._width = max([len(d) for d in self._data]) |
|
|
| def _fill(self): |
| width, filler = self._width, [None] |
| if not width: |
| return |
| for d in self._data: |
| rem = width - len(d) |
| if rem > 0: |
| d.extend(filler * rem) |
| return |
|
|
| @classmethod |
| def from_dict(cls, data, headers=_MISSING, max_depth=1, metadata=None): |
| """Create a Table from a :class:`dict`. Operates the same as |
| :meth:`from_data`, but forces interpretation of the data as a |
| Mapping. |
| """ |
| return cls.from_data(data=data, headers=headers, |
| max_depth=max_depth, _data_type=DictInputType(), |
| metadata=metadata) |
|
|
| @classmethod |
| def from_list(cls, data, headers=_MISSING, max_depth=1, metadata=None): |
| """Create a Table from a :class:`list`. Operates the same as |
| :meth:`from_data`, but forces the interpretation of the data |
| as a Sequence. |
| """ |
| return cls.from_data(data=data, headers=headers, |
| max_depth=max_depth, _data_type=ListInputType(), |
| metadata=metadata) |
|
|
| @classmethod |
| def from_object(cls, data, headers=_MISSING, max_depth=1, metadata=None): |
| """Create a Table from an :class:`object`. Operates the same as |
| :meth:`from_data`, but forces the interpretation of the data |
| as an object. May be useful for some :class:`dict` and |
| :class:`list` subtypes. |
| """ |
| return cls.from_data(data=data, headers=headers, |
| max_depth=max_depth, _data_type=ObjectInputType(), |
| metadata=metadata) |
|
|
| @classmethod |
| def from_data(cls, data, headers=_MISSING, max_depth=1, **kwargs): |
|
|
| """Create a Table from any supported data, heuristically |
| selecting how to represent the data in Table format. |
| |
| Args: |
| data (object): Any object or iterable with data to be |
| imported to the Table. |
| |
| headers (iterable): An iterable of headers to be matched |
| to the data. If not explicitly passed, headers will be |
| guessed for certain datatypes. |
| |
| max_depth (int): The level to which nested Tables should |
| be created (default: 1). |
| |
| _data_type (InputType subclass): For advanced use cases, |
| do not guess the type of the input data, use this data |
| type instead. |
| """ |
| |
| |
| |
| metadata = kwargs.pop('metadata', None) |
| _data_type = kwargs.pop('_data_type', None) |
|
|
| if max_depth < 1: |
| |
| return cls(headers=headers, metadata=metadata) |
| is_seq = isinstance(data, Sequence) |
| if is_seq: |
| if not data: |
| return cls(headers=headers, metadata=metadata) |
| to_check = data[0] |
| if not _data_type: |
| for it in cls._input_types: |
| if it.check_type(to_check): |
| _data_type = it |
| break |
| else: |
| |
| is_seq = False |
| to_check = data |
| else: |
| if type(data) in _DNR: |
| |
| |
| return cls([[data]], headers=headers, metadata=metadata) |
| to_check = data |
| if not _data_type: |
| for it in cls._input_types: |
| if it.check_type(to_check): |
| _data_type = it |
| break |
| else: |
| raise UnsupportedData('unsupported data type %r' |
| % type(data)) |
| if headers is _MISSING: |
| headers = _data_type.guess_headers(to_check) |
| if is_seq: |
| entries = _data_type.get_entry_seq(data, headers) |
| else: |
| entries = [_data_type.get_entry(data, headers)] |
| if max_depth > 1: |
| new_max_depth = max_depth - 1 |
| for i, entry in enumerate(entries): |
| for j, cell in enumerate(entry): |
| if type(cell) in _DNR: |
| |
| continue |
| try: |
| entries[i][j] = cls.from_data(cell, |
| max_depth=new_max_depth) |
| except UnsupportedData: |
| continue |
| return cls(entries, headers=headers, metadata=metadata) |
|
|
| def __len__(self): |
| return len(self._data) |
|
|
| def __getitem__(self, idx): |
| return self._data[idx] |
|
|
| def __repr__(self): |
| cn = self.__class__.__name__ |
| if self.headers: |
| return f'{cn}(headers={self.headers!r}, data={self._data!r})' |
| else: |
| return f'{cn}({self._data!r})' |
|
|
| def to_html(self, orientation=None, wrapped=True, |
| with_headers=True, with_newlines=True, |
| with_metadata=False, max_depth=1): |
| """Render this Table to HTML. Configure the structure of Table |
| HTML by subclassing and overriding ``_html_*`` class |
| attributes. |
| |
| Args: |
| orientation (str): one of 'auto', 'horizontal', or |
| 'vertical' (or the first letter of any of |
| those). Default 'auto'. |
| wrapped (bool): whether or not to include the wrapping |
| '<table></table>' tags. Default ``True``, set to |
| ``False`` if appending multiple Table outputs or an |
| otherwise customized HTML wrapping tag is needed. |
| with_newlines (bool): Set to ``True`` if output should |
| include added newlines to make the HTML more |
| readable. Default ``False``. |
| with_metadata (bool/str): Set to ``True`` if output should |
| be preceded with a Table of preset metadata, if it |
| exists. Set to special value ``'bottom'`` if the |
| metadata Table HTML should come *after* the main HTML output. |
| max_depth (int): Indicate how deeply to nest HTML tables |
| before simply reverting to :func:`repr`-ing the nested |
| data. |
| |
| Returns: |
| A text string of the HTML of the rendered table. |
| |
| """ |
| lines = [] |
| headers = [] |
| if with_metadata and self.metadata: |
| metadata_table = Table.from_data(self.metadata, |
| max_depth=max_depth) |
| metadata_html = metadata_table.to_html(with_headers=True, |
| with_newlines=with_newlines, |
| with_metadata=False, |
| max_depth=max_depth) |
| if with_metadata != 'bottom': |
| lines.append(metadata_html) |
| lines.append('<br />') |
|
|
| if with_headers and self.headers: |
| headers.extend(self.headers) |
| headers.extend([None] * (self._width - len(self.headers))) |
| if wrapped: |
| lines.append(self._html_table_tag) |
| orientation = orientation or 'auto' |
| ol = orientation[0].lower() |
| if ol == 'a': |
| ol = 'h' if len(self) > 1 else 'v' |
| if ol == 'h': |
| self._add_horizontal_html_lines(lines, headers=headers, |
| max_depth=max_depth) |
| elif ol == 'v': |
| self._add_vertical_html_lines(lines, headers=headers, |
| max_depth=max_depth) |
| else: |
| raise ValueError("expected one of 'auto', 'vertical', or" |
| " 'horizontal', not %r" % orientation) |
| if with_metadata and self.metadata and with_metadata == 'bottom': |
| lines.append('<br />') |
| lines.append(metadata_html) |
|
|
| if wrapped: |
| lines.append(self._html_table_tag_close) |
| sep = '\n' if with_newlines else '' |
| return sep.join(lines) |
|
|
| def get_cell_html(self, value): |
| """Called on each value in an HTML table. By default it simply escapes |
| the HTML. Override this method to add additional conditions |
| and behaviors, but take care to ensure the final output is |
| HTML escaped. |
| """ |
| return escape_html(value) |
|
|
| def _add_horizontal_html_lines(self, lines, headers, max_depth): |
| esc = self.get_cell_html |
| new_depth = max_depth - 1 if max_depth > 1 else max_depth |
| if max_depth > 1: |
| new_depth = max_depth - 1 |
| if headers: |
| _thth = self._html_th_close + self._html_th |
| lines.append(self._html_thead) |
| lines.append(self._html_tr + self._html_th + |
| _thth.join([esc(h) for h in headers]) + |
| self._html_th_close + self._html_tr_close) |
| lines.append(self._html_thead_close) |
| trtd, _tdtd, _td_tr = (self._html_tr + self._html_td, |
| self._html_td_close + self._html_td, |
| self._html_td_close + self._html_tr_close) |
| lines.append(self._html_tbody) |
| for row in self._data: |
| if max_depth > 1: |
| _fill_parts = [] |
| for cell in row: |
| if isinstance(cell, Table): |
| _fill_parts.append(cell.to_html(max_depth=new_depth)) |
| else: |
| _fill_parts.append(esc(cell)) |
| else: |
| _fill_parts = [esc(c) for c in row] |
| lines.append(''.join([trtd, _tdtd.join(_fill_parts), _td_tr])) |
| lines.append(self._html_tbody_close) |
|
|
| def _add_vertical_html_lines(self, lines, headers, max_depth): |
| esc = self.get_cell_html |
| new_depth = max_depth - 1 if max_depth > 1 else max_depth |
| tr, th, _th = self._html_tr, self._html_th, self._html_th_close |
| td, _tdtd = self._html_td, self._html_td_close + self._html_td |
| _td_tr = self._html_td_close + self._html_tr_close |
| for i in range(self._width): |
| line_parts = [tr] |
| if headers: |
| line_parts.extend([th, esc(headers[i]), _th]) |
| if max_depth > 1: |
| new_depth = max_depth - 1 |
| _fill_parts = [] |
| for row in self._data: |
| cell = row[i] |
| if isinstance(cell, Table): |
| _fill_parts.append(cell.to_html(max_depth=new_depth)) |
| else: |
| _fill_parts.append(esc(row[i])) |
| else: |
| _fill_parts = [esc(row[i]) for row in self._data] |
| line_parts.extend([td, _tdtd.join(_fill_parts), _td_tr]) |
| lines.append(''.join(line_parts)) |
|
|
| def to_text(self, with_headers=True, maxlen=None): |
| """Get the Table's textual representation. Only works well |
| for Tables with non-recursive data. |
| |
| Args: |
| with_headers (bool): Whether to include a header row at the top. |
| maxlen (int): Max length of data in each cell. |
| """ |
| lines = [] |
| widths = [] |
| headers = list(self.headers) |
| text_data = [[to_text(cell, maxlen=maxlen) for cell in row] |
| for row in self._data] |
| for idx in range(self._width): |
| cur_widths = [len(cur) for cur in text_data] |
| if with_headers: |
| cur_widths.append(len(to_text(headers[idx], maxlen=maxlen))) |
| widths.append(max(cur_widths)) |
| if with_headers: |
| lines.append(' | '.join([h.center(widths[i]) |
| for i, h in enumerate(headers)])) |
| lines.append('-|-'.join(['-' * w for w in widths])) |
| for row in text_data: |
| lines.append(' | '.join([cell.center(widths[j]) |
| for j, cell in enumerate(row)])) |
| return '\n'.join(lines) |
|
|