[Python2] Win7(x64)下安装Py2.7、pip，以及错误UnicodeEncodeError的解决方案

环境

Win7 (x64) 中文

安装Python以及Pip

Python2 （默认安装到C:\Python27下）

下载链接：https://www.python.org/downloads/

记得将该目录添加到系统环境变量中

安装setuptools

下载链接：https://pypi.python.org/pypi/setuptools#downloads

　下载Source的压缩包文件，解压后用cmd进入到解压后的文件所在的目录执行命令：

　python setup.py install

安装pip

下载链接：https://pypi.python.org/pypi/pip#downloads

安装方法同setuptools

安装完成后easy_install、pip均在目录 C:\Python27\Scripts（记得将该目录添加到系统环境变量中）

使用Pip安装扩展库

比如安装requests库：pip install requests

报错如下：

…省略…

File “C:\Python27\lib\site-packages\pip-9.0.1-py2.7.egg\pip_vendor\colorama\ansitowin32.py”, line 174, in write_plain_text

self.wrapped.write(text[start:end])

UnicodeEncodeError: ‘ascii’ codec can’t encode character u’\u258b’ in position 8: ordinal not in range(128)

解决方案：

找到文件ansitowin32.py，并在文件开头加上

import sys

reload(sys)

sys.setdefaultencoding(‘gbk’) #gbk编码在cmd下使用pip install进度条正常显示，此处需根据自己需求更改该编码

此处特地标红了reload(sys)语句，如果不加这条语句，会出现错误：

AttributeError: ‘module’ object has no attribute ‘setdefaultencoding’

先看Python2.7模块加载过程：

C:\Documents and Settings\Administrator\桌面>python -v
# installing zipimport hook
import zipimport # builtin
# installed zipimport hook
# C:\Python27\lib\site.pyc matches C:\Python27\lib\site.py
import site # precompiled from C:\Python27\lib\site.pyc
# C:\Python27\lib\os.pyc matches C:\Python27\lib\os.py
import os # precompiled from C:\Python27\lib\os.pyc
import errno # builtin
import nt # builtin
# C:\Python27\lib\ntpath.pyc matches C:\Python27\lib\ntpath.py
import ntpath # precompiled from C:\Python27\lib\ntpath.pyc
# C:\Python27\lib\stat.pyc matches C:\Python27\lib\stat.py
import stat # precompiled from C:\Python27\lib\stat.pyc
# C:\Python27\lib\genericpath.pyc matches C:\Python27\lib\genericpath.py
import genericpath # precompiled from C:\Python27\lib\genericpath.pyc
# C:\Python27\lib\warnings.pyc matches C:\Python27\lib\warnings.py
import warnings # precompiled from C:\Python27\lib\warnings.pyc

首先会加载C:\Python2.7\lib\site.py文件，在site.py文件中的main函数最后两句代码：

def main():
global ENABLE_USER_SITE
abs__file__()
known_paths = removeduppaths()
if (os.name == "posix" and sys.path and
os.path.basename(sys.path[-1]) == "Modules"):
addbuilddir()
if ENABLE_USER_SITE is None:
ENABLE_USER_SITE = check_enableusersite()
known_paths = addusersitepackages(known_paths)
known_paths = addsitepackages(known_paths)
if sys.platform == 'os2emx':
setBEGINLIBPATH()
setquit()
setcopyright()
sethelper()
aliasmbcs()
setencoding()
execsitecustomize()
if ENABLE_USER_SITE:
execusercustomize()
# Remove sys.setdefaultencoding() so that users cannot change the encoding after initialization. The test for presence is needed when this module is run as a script, because this code is executed twice.
if hasattr(sys, "setdefaultencoding"):
del sys.setdefaultencoding

在加载sys后，setdefaultencoding函数被删除了，所以需要重新加载sys。

一劳永逸的方案

在python的Lib\site-packages文件夹下新建一个sitecustomize.py，内容为：

import sys

reload(sys)

sys.setdefaultencoding(‘gbk’)

python启动的时候会调用sitecustomize.py文件设置系统的默认编码，而不需要每次都手动的在错误文件上加这三行代码。

Reference

http://liguangming.com/how-to-use-utf-8-with-python

http://blog.csdn.net/intel80586/article/details/8566057