Question

Using python 2.7 I get this error:

    Traceback (most recent call last):
  File "/usr/lib/python2.7/runpy.py", line 162, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "/usr/lib/python2.7/runpy.py", line 72, in _run_code
    exec code in run_globals
  File "/usr/lib/python2.7/cProfile.py", line 199, in <module>
    main()
  File "/usr/lib/python2.7/cProfile.py", line 165, in main
    from optparse import OptionParser
  File "/usr/lib/python2.7/optparse.py", line 77, in <module>
    import textwrap
  File "/usr/lib/python2.7/textwrap.py", line 32, in <module>
    class TextWrapper:
  File "/usr/lib/python2.7/textwrap.py", line 74, in TextWrapper
    whitespace_trans = string.maketrans(_whitespace, ' ' * len(_whitespace))
AttributeError: 'module' object has no attribute 'maketrans'

while running this simple code:

def blah():
    orig = ""
    for i in range(1000000):
        orig += "zim";
blah()

using this call:

$ python -m cProfile string.py

I’m using Ubuntu Natty Narwhal, and installed the package python-profiler (I don’t know if this is necessary).

Answer 1

As the Python tutorial on modules explains:

Actually, modules are searched in the list of directories given by the variable sys.path which is initialized from the directory containing the input script (or the current directory), PYTHONPATH and the installation- dependent default. This allows Python programs that know what they’re doing to modify or replace the module search path. Note that because the directory containing the script being run is on the search path, it is important that the script not have the same name as a standard module, or Python will attempt to load the script as a module when that module is imported.

textwrap does import string. Your script is named string.py and comes first (or at least before the stdlib directories) on the search path, so it is imported. But it doesn’t define the functions and constants expected, e.g. it doesn’t have a maketrans module. That’s what the error tells you.

(The same error should occur if you just run the script without profiling.)