Source code for matplotlib._api

Helper functions for managing the Matplotlib API.

This documentation is only relevant for Matplotlib developers, not for users.

.. warning:

    This module and its submodules are for internal use only.  Do not use them
    in your own code.  We may change the API at any time with no warning.


import itertools
import re
import sys
import warnings

from .deprecation import (
    deprecated, warn_deprecated,
    rename_parameter, delete_parameter, make_keyword_only,
    deprecate_method_override, deprecate_privatize_attribute,

[docs]class classproperty: """ Like `property`, but also triggers on access via the class, and it is the *class* that's passed as argument. Examples -------- :: class C: @classproperty def foo(cls): return cls.__name__ assert == "C" """ def __init__(self, fget, fset=None, fdel=None, doc=None): self._fget = fget if fset is not None or fdel is not None: raise ValueError('classproperty only implements fget.') self.fset = fset self.fdel = fdel # docs are ignored for now self._doc = doc def __get__(self, instance, owner): return self._fget(owner) @property def fget(self): return self._fget
# In the following check_foo() functions, the first parameter starts with an # underscore because it is intended to be positional-only (e.g., so that # `_api.check_isinstance([...], types=foo)` doesn't fail.
[docs]def check_isinstance(_types, **kwargs): """ For each *key, value* pair in *kwargs*, check that *value* is an instance of one of *_types*; if not, raise an appropriate TypeError. As a special case, a ``None`` entry in *_types* is treated as NoneType. Examples -------- >>> _api.check_isinstance((SomeClass, None), arg=arg) """ types = _types none_type = type(None) types = ((types,) if isinstance(types, type) else (none_type,) if types is None else tuple(none_type if tp is None else tp for tp in types)) def type_name(tp): return ("None" if tp is none_type else tp.__qualname__ if tp.__module__ == "builtins" else f"{tp.__module__}.{tp.__qualname__}") for k, v in kwargs.items(): if not isinstance(v, types): names = [*map(type_name, types)] if "None" in names: # Move it to the end for better wording. names.remove("None") names.append("None") raise TypeError( "{!r} must be an instance of {}, not a {}".format( k, ", ".join(names[:-1]) + " or " + names[-1] if len(names) > 1 else names[0], type_name(type(v))))
[docs]def check_in_list(_values, *, _print_supported_values=True, **kwargs): """ For each *key, value* pair in *kwargs*, check that *value* is in *_values*. Parameters ---------- _values : iterable Sequence of values to check on. _print_supported_values : bool, default: True Whether to print *_values* when raising ValueError. **kwargs : dict *key, value* pairs as keyword arguments to find in *_values*. Raises ------ ValueError If any *value* in *kwargs* is not found in *_values*. Examples -------- >>> _api.check_in_list(["foo", "bar"], arg=arg, other_arg=other_arg) """ values = _values for key, val in kwargs.items(): if val not in values: if _print_supported_values: raise ValueError( f"{val!r} is not a valid value for {key}; " f"supported values are {', '.join(map(repr, values))}") else: raise ValueError(f"{val!r} is not a valid value for {key}")
[docs]def check_shape(_shape, **kwargs): """ For each *key, value* pair in *kwargs*, check that *value* has the shape *_shape*, if not, raise an appropriate ValueError. *None* in the shape is treated as a "free" size that can have any length. e.g. (None, 2) -> (N, 2) The values checked must be numpy arrays. Examples -------- To check for (N, 2) shaped arrays >>> _api.check_shape((None, 2), arg=arg, other_arg=other_arg) """ target_shape = _shape for k, v in kwargs.items(): data_shape = v.shape if len(target_shape) != len(data_shape) or any( t not in [s, None] for t, s in zip(target_shape, data_shape) ): dim_labels = iter(itertools.chain( 'MNLIJKLH', (f"D{i}" for i in itertools.count()))) text_shape = ", ".join((str(n) if n is not None else next(dim_labels) for n in target_shape)) raise ValueError( f"{k!r} must be {len(target_shape)}D " f"with shape ({text_shape}). " f"Your input has shape {v.shape}." )
[docs]def check_getitem(_mapping, **kwargs): """ *kwargs* must consist of a single *key, value* pair. If *key* is in *_mapping*, return ``_mapping[value]``; else, raise an appropriate ValueError. Examples -------- >>> _api.check_getitem({"foo": "bar"}, arg=arg) """ mapping = _mapping if len(kwargs) != 1: raise ValueError("check_getitem takes a single keyword argument") (k, v), = kwargs.items() try: return mapping[v] except KeyError: raise ValueError( "{!r} is not a valid value for {}; supported values are {}" .format(v, k, ', '.join(map(repr, mapping)))) from None
[docs]def warn_external(message, category=None): """ `warnings.warn` wrapper that sets *stacklevel* to "outside Matplotlib". The original emitter of the warning can be obtained by patching this function back to `warnings.warn`, i.e. ``_api.warn_external = warnings.warn`` (or ``functools.partial(warnings.warn, stacklevel=2)``, etc.). """ frame = sys._getframe() for stacklevel in itertools.count(1): # lgtm[py/unused-loop-variable] if frame is None: # when called in embedded context may hit frame is None break if not re.match(r"\A(matplotlib|mpl_toolkits)(\Z|\.(?!tests\.))", # Work around sphinx-gallery not setting __name__. frame.f_globals.get("__name__", "")): break frame = frame.f_back warnings.warn(message, category, stacklevel)