mypythontools.types package

Module with some helpers for type hints and annotations.

mypythontools.types.get_return_type_hints(func: Callable) → Any[source]

Return function return types. .. note:

This is not working on older versions that 3.9. It will not raise, but return None. If you need it on
3.7, you can use `get_return_type_hints_evaluated`.
Parameters

func (Callable) – Function with type hints.

Returns

Type of return. E.g. <class ‘tuple’> or typing_extensions.Literal[‘int’, ‘float’].

Return type

Any

Example

>>> # You can use Union as well as Literal
>>> def union_return() -> int | float:
...     return 1
>>> inferred_type = get_return_type_hints(union_return)
>>> 'int' in str(inferred_type) and 'float' in str(inferred_type)  
True
>>> def literal_return() -> Literal[1, 2, 3]:
...     return 1
>>> inferred_type = get_return_type_hints(literal_return)
>>> 'Literal' in str(inferred_type)  
True
mypythontools.types.get_type_hints(*args, **kwargs)[source]
mypythontools.types.json_to_py(json: dict, replace_comma_decimal: bool = True, replace_true_false: bool = True) → Any[source]

Take json and eval it from strings. If string to string, if float to float, if object then to dict.

When to use? - If sending object as parameter in function.

Parameters

  • json (dict) – JSON with various formats as string.

  • replace_comma_decimal (bool, optional) – Some countries use comma as decimal separator (e.g. 12,3). If True, comma replaced with dot (Only if there are no brackets (list, dict…) and if not converted to number string remain untouched) . For example ‘2,6’ convert to 2.6. Defaults to True

  • replace_true_false (bool, optional) – If string is ‘false’ or ‘true’ (for example from javascript), it will be capitalized first for correct type conversion. Defaults to True

Returns

Python dictionary with correct types.

Return type

dict

Example

>>> # Can be beneficial for example when communicating with JavaScript
>>> json_to_py({'one_two': '1,2'})
{'one_two': 1.2}
mypythontools.types.small_validate(value, allowed_type: None | Any = None, name: str | None = None) → None[source]

Type validation. It also works for Union and validate Literal values.

Instead of typeguard validation, it define just subset of types, but is simplier and needs no extra import, therefore can be faster.

Parameters

  • value (Any) – Value that will be validated.

  • allowed_type (Any, optional) – For example int, str or list. It can be also Union or Literal. If Literal, validated value has to be one of Literal values. If None, it’s skipped. Defaults to None.

  • name (str | None, optional) – If error raised, name will be printed. Defaults to None.

Raises

TypeError – Type does not fit.

Examples

>>> from typing_extensions import Literal
...
>>> small_validate(1, int)
>>> small_validate(None, Union[list, None])
>>> small_validate("two", Literal["one", "two"])
>>> small_validate("three", Literal["one", "two"])
Traceback (most recent call last):
ValidationError: ...
mypythontools.types.str_to_bool(bool_str)[source]

Convert string to bool. Usually used from argparse. Raise error if don’t know what value.

Possible values for True: ‘yes’, ‘true’, ‘t’, ‘y’, ‘1’ Possible values for False: ‘no’, ‘false’, ‘f’, ‘n’, ‘0’

Parameters

bool_str (str) –

Raises

TypeError – If not one of bool values inferred, error is raised.

Returns

True or False

Return type

bool

Example

>>> str_to_bool("y")
True

Argparse example:

parser = argparse.ArgumentParser()

parser.add_argument(
    "--test",
    choices=(True, False),
    type=str_to_bool,
    nargs="?",
)
mypythontools.types.str_to_infer_type(string_var: str) → Any[source]

Convert string to another type (for example to int, float, list or dict).

Parameters

string_var (str) – String that should be converted.

Returns

New inferred type.

Return type

Any

Examples

>>> type(str_to_infer_type("1"))
<class 'int'>
>>> type(str_to_infer_type("1.2"))
<class 'float'>
>>> type(str_to_infer_type("['one']"))
<class 'list'>
>>> type(str_to_infer_type("{'one': 1}"))
<class 'dict'>
mypythontools.types.typechecked_compatible(function)[source]

Turns off type checking for old incompatible python versions.

Mainly for new syntax like list[str] which raise TypeError.

mypythontools.types.validate_sequence(value, variable)[source]

Ensure, that defined sequence is not just a string.

Usually with Sequence we means for example tuple or list of items. String in some cases is not valid type then. This ensure, that this is Sequence, but not just string.

Parameters

  • value (Sequence) – Variable where we want to ensure Sequence type.

  • variable (_type_) – If it is just string, this will raise an error with name of variable with incorrect type.

Raises

TypeError – If it is just a string.

Submodules