python 是2.7.5，pip总出错

Traceback (most recent call last):
  File "/usr/local/bin/pip", line 9, in <module>
    load_entry_point('pip==1.4', 'console_scripts', 'pip')()
  File "/Library/Python/2.7/site-packages/distribute-0.6.49-py2.7.egg/pkg_resources.py", line 345, in load_entry_point
    return get_distribution(dist).load_entry_point(group, name)
  File "/Library/Python/2.7/site-packages/distribute-0.6.49-py2.7.egg/pkg_resources.py", line 2381, in load_entry_point
    return ep.load()
  File "/Library/Python/2.7/site-packages/distribute-0.6.49-py2.7.egg/pkg_resources.py", line 2087, in load
    entry = __import__(self.module_name, globals(),globals(), ['__name__'])
ImportError: No module named pip