函数校验

判断一个callable对象是否是函数

>>> import os
>>> import types
>>> 
>>> for item in dir(os):
    if isinstance(eval('.'.join(['os', item])), types.FunctionType):
        print item

        
_execvpe
_exists
_get_exports_list
_make_stat_result
_make_statvfs_result
_pickle_stat_result
_pickle_statvfs_result
execl
execle
execlp
execlpe
execvp
execvpe
getenv
makedirs
removedirs
renames
spawnl
spawnle
unsetenv
walk

当然：也可以直接用内置函数type()