的Python 3.4 - 无法导入模块

Question

我想使用对开模块，但是当我尝试import bisect我得到这个错误 ：

NameError: global name 'bisect_left' is not defined 

而这个错误，当我尝试from bisect import bisect_left：

ImportError: cannot import name bisect_left 

我试图从python文档中使用这个函数：

def index(a, x): 
    'Locate the leftmost value exactly equal to x' 
    i = bisect_left(a, x) 
    if i != len(a) and a[i] == x: 
     return i 
    else: 
     return False 

我在做什么错？

Answer 1

您将您的脚本命名为bisect.py;它正在导入，而不是标准库：

nidhogg:stackoverflow-3.4 mj$ cat bisect.py 
import bisect 

bisect.bisect_left 
nidhogg:stackoverflow-3.4 mj$ bin/python bisect.py 
Traceback (most recent call last): 
    File "bisect.py", line 1, in <module> 
    import bisect 
    File "/Users/mj/Development/venvs/stackoverflow-3.4/bisect.py", line 3, in <module> 
    bisect.bisect_left 
AttributeError: 'module' object has no attribute 'bisect_left' 
nidhogg:stackoverflow-3.4 mj$ echo 'from bisect import bisect_left' > bisect.py 
nidhogg:stackoverflow-3.4 mj$ bin/python bisect.py 
Traceback (most recent call last): 
    File "bisect.py", line 1, in <module> 
    from bisect import bisect_left 
    File "/Users/mj/Development/venvs/stackoverflow-3.4/bisect.py", line 1, in <module> 
    from bisect import bisect_left 
ImportError: cannot import name 'bisect_left' 

重命名该脚本以免掩盖它。