| """ A universal module with functions / classes without dependencies. """ |
| import functools |
| import re |
| import os |
|
|
|
|
| _sep = os.path.sep |
| if os.path.altsep is not None: |
| _sep += os.path.altsep |
| _path_re = re.compile(r'(?:\.[^{0}]+|[{0}]__init__\.py)$'.format(re.escape(_sep))) |
| del _sep |
|
|
|
|
| def to_list(func): |
| def wrapper(*args, **kwargs): |
| return list(func(*args, **kwargs)) |
| return wrapper |
|
|
|
|
| def to_tuple(func): |
| def wrapper(*args, **kwargs): |
| return tuple(func(*args, **kwargs)) |
| return wrapper |
|
|
|
|
| def unite(iterable): |
| """Turns a two dimensional array into a one dimensional.""" |
| return set(typ for types in iterable for typ in types) |
|
|
|
|
| class UncaughtAttributeError(Exception): |
| """ |
| Important, because `__getattr__` and `hasattr` catch AttributeErrors |
| implicitly. This is really evil (mainly because of `__getattr__`). |
| Therefore this class originally had to be derived from `BaseException` |
| instead of `Exception`. But because I removed relevant `hasattr` from |
| the code base, we can now switch back to `Exception`. |
| |
| :param base: return values of sys.exc_info(). |
| """ |
|
|
|
|
| def safe_property(func): |
| return property(reraise_uncaught(func)) |
|
|
|
|
| def reraise_uncaught(func): |
| """ |
| Re-throw uncaught `AttributeError`. |
| |
| Usage: Put ``@rethrow_uncaught`` in front of the function |
| which does **not** suppose to raise `AttributeError`. |
| |
| AttributeError is easily get caught by `hasattr` and another |
| ``except AttributeError`` clause. This becomes problem when you use |
| a lot of "dynamic" attributes (e.g., using ``@property``) because you |
| can't distinguish if the property does not exist for real or some code |
| inside of the "dynamic" attribute through that error. In a well |
| written code, such error should not exist but getting there is very |
| difficult. This decorator is to help us getting there by changing |
| `AttributeError` to `UncaughtAttributeError` to avoid unexpected catch. |
| This helps us noticing bugs earlier and facilitates debugging. |
| """ |
| @functools.wraps(func) |
| def wrapper(*args, **kwds): |
| try: |
| return func(*args, **kwds) |
| except AttributeError as e: |
| raise UncaughtAttributeError(e) from e |
| return wrapper |
|
|
|
|
| class PushBackIterator: |
| def __init__(self, iterator): |
| self.pushes = [] |
| self.iterator = iterator |
| self.current = None |
|
|
| def push_back(self, value): |
| self.pushes.append(value) |
|
|
| def __iter__(self): |
| return self |
|
|
| def __next__(self): |
| if self.pushes: |
| self.current = self.pushes.pop() |
| else: |
| self.current = next(self.iterator) |
| return self.current |
|
|