Skip to main content
Join the official Python Developers Survey 2018 and win valuable prizes: Start the survey!

This module provides dynamic type check mechanism.

Project description

This module provides dynamic type check mechanism.

Normal Type Check:

>>> from typechecker import typeinfo, list_, tuple_, has_attrs
>>> @typeinfo(int, x=int, y=int)
... def add(x, y):
...     return x + y
>>> add(10, 20)
30
>>> add('aa', 'bb')
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "typechecker/typeinfo.py", line 113, in call
    _check_arg(f, assigned, types)
  File "typechecker/typeinfo.py", line 84, in _check_arg
    f.__name__))
TypeError: In function add, argument "y" required "int". "str" found.

Tuple Type Check:

>>> @typeinfo(int, val=tuple_(int, str))
... def test(val):
...     return len(val)
...
>>> test((19, 'aaa'))
2
>>> test('aaa')
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "typechecker/typeinfo.py", line 113, in call
    _check_arg(f, assigned, types)
  File "typechecker/typeinfo.py", line 84, in _check_arg
    f.__name__))
TypeError: In function test, argument "val" required "tuple[int, str]". "str" found.

List Type Check:

>>> @typeinfo(int, val=list_(int))
... def test(val):
...     return 10
...
>>> test([1,2,3])
10
>>> test([1,2,'aaa'])
Traceback (most recent call last):
  File "typechecker/typeinfo.py", line 113, in call
    _check_arg(f, assigned, types)
  File "typechecker/typeinfo.py", line 84, in _check_arg
    f.__name__))
TypeError: In function test, argument "val" required "list[int]". "list" found.

Complex Type Check:

>>> @typeinfo(int, val=tuple_(list_(int)))
... def test(val):
...     return 10
...
>>> test(([1],))
10
>>> test((['aa'],))
Traceback (most recent call last):
  File "/usr/local/python2.7/lib/python2.7/doctest.py", line 1254, in __run
    compileflags, 1) in test.globs
  File "<doctest typechecker[12]>", line 1, in <module>
    test((['aa'],))
  File "typechecker/typeinfo.py", line 113, in call
    _check_arg(f, assigned, types)
  File "typechecker/typeinfo.py", line 84, in _check_arg
    f.__name__))
TypeError: In function test, argument "val" required "tuple[list[int]]". "tuple" found.

Structural subtyping:

>>> @typeinfo(int, f=Callable)
... def test(f):
...     return 10
...
>>> test(map)
10
>>> test(1)
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "typechecker/typeinfo.py", line 113, in call
    _check_arg(f, assigned, types)
  File "typechecker/typeinfo.py", line 84, in _check_arg
    f.__name__))
TypeError: In function test, argument "f" required "hasattr[__call__]". "int" found.

And check:

>>> @typeinfo(int, f=and_(Callable, ContextManager))
... def test(f):
...     return 10
...
>>> test(file)
10
>>> test(map)
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "typechecker/typeinfo.py", line 113, in call
    _check_arg(f, assigned, types)
  File "typechecker/typeinfo.py", line 84, in _check_arg
    f.__name__))
TypeError: In function test, argument "f" required "And[hasattr[__call__], hasattr[__enter__, __exit__]]". "builtin_function_or_method" found.

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Filename, size & hash SHA256 hash help File type Python version Upload date
typechecker-0.1.1.tar.gz (4.1 kB) Copy SHA256 hash SHA256 Source None Jul 9, 2011

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN SignalFx SignalFx Supporter DigiCert DigiCert EV certificate StatusPage StatusPage Status page