无法在Python 2.7或Python 3.3中导入十进制

Question

我无法import decimal在Python 2.7或3.3的终端中使用.

以下是我得到的错误:

Python 3.3.0 (v3.3.0:bd8afb90ebf2, Sep 29 2012, 01:25:11) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import decimal
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Library/Frameworks/Python.framework/Versions/3.3/lib/python3.3/decimal.py", line 3849, in <module>
    _numbers.Number.register(Decimal)
AttributeError: 'module' object has no attribute 'Number'

或Python 2.7

Python 2.7.2 (default, Oct 11 2012, 20:14:37) 
[GCC 4.2.1 Compatible Apple Clang 4.0 (tags/Apple/clang-418.0.60)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import decimal
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/decimal.py", line 141, in <module>
    import numbers as _numbers
  File "numbers.py", line 34, in <module>
    assert x / y == 2.5 # true division of x by y
AssertionError

如何导入小数？

Answer 1

有没有numbers.py在当前的工作目录？

这可能是问题的原因,因为这会阻止导入标准库模块号.

Answer 2

如何在Python3中导入小数：

from decimal import Decimal
a = Decimal(25)
print(type(a))

//prints <class 'decimal.Decimal'>