PyBackport: Builtins

py_back.builtins

Module to backport 'builtins' classes depending on the system python.

py_back allows using the builtins module just as the original.

# Python version lower than 3.9
>>> from py_back.builtins import str
>>> my_string = str("Hello world!")
>>> print(my_string.removesuffix("!"))
Hello world

Note

Python builtins don't require to be imported, but the backported builtins do not follow this rule. This results in the inconvenience that backported instances must be defined with the constructor provided by py_back, even if they interact with other not backported builtins.

dict

Bases: builtins.dict

Backport for 'dict' class.

  • dict() -> new empty dictionary.
  • dict(mapping) -> new dictionary initialized from a mapping object's (key, value) pairs.
  • dict(iterable) -> new dictionary initialized as if.
  • dict(**kwargs) -> new dictionary initialized with the name=value pairs in the keyword argument list. E.G.: dict(one=1, two=2)
Backports

Python 3.9: Operators d | other and d |= other.

__or__ 

__or__(other: builtins.dict) -> dict

Return self | other, which is equivalent to self.update(other).

Create a new dictionary with the merged keys and values of d and other, which must both be dictionaries. The values of other take priority when d and other share keys.

The operation other | d is also supported.

Notes

The dictionary defined as other does not need to be a backported instance.

Examples:

>>> from py_back.builtins import dict
>>> dict({"key_0": 1}) | {"key_1": 2}
{"key_0": 1, "key_1": 2}

str

Bases: builtins.str

Backport for str class.

  • str(object='') -> str
  • str(bytes_or_buffer[, encoding[, errors]]) -> str
Backports

Python 3.9: Methods str.removeprefix(prefix, /) and str.removesuffix(suffix, /)

removeprefix 

removeprefix(prefix: str) -> str

Backport logic to remove prefix from str.

If the string starts with the prefix string, return string[len(prefix):]. Otherwise, return a copy of the original string.

Examples:

from py_back.builtins import str
>>> str('TestHook').removeprefix('Test')
'Hook'
>>> str('BaseTestCase').removeprefix('Test')
'BaseTestCase'

removesuffix 

removesuffix(suffix: str) -> str

Backport logic to remove suffix from str.

If the string ends with the suffix string and that suffix is not empty, return string[:-len(suffix)]. Otherwise, return a copy of the original string.

Examples:

from py_back.builtins import str
>>> str('MiscTests').removesuffix('Tests')
'Misc'
>>> str('TmpDirMixin').removesuffix('Tests')
'TmpDirMixin'