#335 string and string methods handling

[Boris Egorov]

pychecker --version
0.8.19

I tried to check ipython project with pychecker. It gives me " INTERNAL ERROR -- STOPPED PROCESSING FUNCTION --"

Some investigation shows that:

• 'str' type doesn't have 'format' method in pycheker internals. It was the problem which triggers error. I saw a list of builtin methods with ipython:

  from pychecker import python
  python.BUILTIN_METHODS.get(str)

See missing_format.py. Example output:

Processing module missing_format (missing_format.py)...

missing_format.py:3: INTERNAL ERROR -- STOPPED PROCESSING FUNCTION --
        Traceback (most recent call last):
          File "/usr/lib/python2.7/dist-packages/pychecker/warn.py", line 242, in _checkFunction
            _checkCode(code, codeSource)
          File "/usr/lib/python2.7/dist-packages/pychecker/warn.py", line 153, in _checkCode
            dispatch_func(oparg, operand, codeSource, code)
          File "/usr/lib/python2.7/dist-packages/pychecker/CodeChecks.py", line 1690, in _CALL_FUNCTION
            _handleFunctionCall(codeSource, code, oparg)
          File "/usr/lib/python2.7/dist-packages/pychecker/CodeChecks.py", line 474, in _handleFunctionCall
            check_arg_count)
          File "/usr/lib/python2.7/dist-packages/pychecker/CodeChecks.py", line 250, in _checkBuiltin
            _validateKwArgs(code, methodInfo, func_name[1], kwArgs)
          File "/usr/lib/python2.7/dist-packages/pychecker/CodeChecks.py", line 192, in _validateKwArgs
            if len(info) < 4:
        TypeError: object of type 'NoneType' has no len()

• pychecker can't deduce type of string without a variable (string literal): the same problem don't appear if I use the same example with "string_contents" instead of variable 'src = "string_contents"'. I found a code in CodeChecks.py which determine a type of a variable, it looks like this:

  objType = code.typeMap.get(utils.safestr(func_name[0]), [])
  

Pychecker probably need to distinguish variable from literals to handle such cases. Example for the second problem is in str_handling.py.

[Boris Egorov]

Example for the second problem