Python type inferencer
Project description
Pytype
Pytype is a static analyzer for Python code.
License
Apache 2.0
Abstract
pytype can statically analyze your Python code, and point out bugs and errors it finds. It works on any kind of code, and doesn’t need any special directives to be useful.
However, it can additionally verify (and leverage) type annotations.
Source
Pytype’s sources can be found on github: https://github.com/google/pytype/
Installation
Install pytype from pip
$ pip install pytype
Usage
NOTE: pytype analyzes a single file. To analyze an entire project, use the included pytype-all tool.
For more detailed explanations of pytype’s error messages, see this doc
Usage: pytype [options] file.py
Infer/check types in a Python module
Selected options:
-h, --help Show the full list of options
-C, --check Don't do type inference. Only check for type errors.
-o OUTPUT, --output=OUTPUT
Output file. Use '-' for stdout.
-V PYTHON_VERSION, --python_version=PYTHON_VERSION
Python version to emulate ("major.minor", e.g. "2.7")
Example
Consider the following code, which uses the type annotation syntax from PEP 3107 and PEP 484 to declare the parameter and return types of the function f:
$ cat t.py def f(x: int, y: str = 'default') -> int: return "foo"
Note that the code above has a bug: The return type is declared to be an integer, but the function actually returns a string.
Now check it with pytype:
$ pytype -V 3.6 t.py File "t.py", line 2, in f: bad option in return type [bad-return-type] Expected: int Actually returned: str
Pytype can also infer type annotations if they are not explicitly provided.
$ cat t.py
class A(object):
def __init__(self):
self.x = 10
p = A()
q = p.x
Run pytype in inference mode (using the -o or --output option):
$ pytype t.py -o -
p = ... # type: A
q = ... # type: int
class A(object):
x = ... # type: int
Release history Release notifications | RSS feed
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.
