Python 3.6.4 / win10 使用pip安装keras时遇到依赖的PyYAML安装出错

PS C:\Users\myjac\Desktop\simple-chinese-ocr> pip install keras
Collecting keras
  Downloading http://mirrors.aliyun.com/pypi/packages/68/89/58ee5f56a9c26957d97217db41780ebedca3154392cb903c3f8a08a52208/Keras-2.1.2-py2.py3-none-any.whl (304kB)
    100% |████████████████████████████████| 307kB 4.7MB/s
Collecting scipy>=0.14 (from keras)
  Downloading http://mirrors.aliyun.com/pypi/packages/09/e9/89a97bcdbdc7aaafea93b6638f9b167ab599b58b5f9832c5a589e8e5d005/scipy-1.0.0-cp36-none-win32.whl (26.0MB)
    100% |████████████████████████████████| 26.0MB 11.4MB/s
Requirement already satisfied: six>=1.9.0 in c:\users\myjac\appdata\local\programs\python\python36-32\lib\site-packages (from keras)
Requirement already satisfied: numpy>=1.9.1 in c:\users\myjac\appdata\local\programs\python\python36-32\lib\site-packages (from keras)
Collecting pyyaml (from keras)
  Downloading http://mirrors.aliyun.com/pypi/packages/4a/85/db5a2df477072b2902b0eb892feb37d88ac635d36245a72a6a69b23b383a/PyYAML-3.12.tar.gz (253kB)
    100% |████████████████████████████████| 256kB 12.8MB/s
Installing collected packages: scipy, pyyaml, keras
  Running setup.py install for pyyaml ... error
Exception:
Traceback (most recent call last):
  File "c:\users\myjac\appdata\local\programs\python\python36-32\lib\site-packages\pip\compat\__init__.py", line 73, in console_to_str
    return s.decode(sys.__stdout__.encoding)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xce in position 68: invalid continuation byte

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:\users\myjac\appdata\local\programs\python\python36-32\lib\site-packages\pip\basecommand.py", line 215, in main
    status = self.run(options, args)
  File "c:\users\myjac\appdata\local\programs\python\python36-32\lib\site-packages\pip\commands\install.py", line 342, in run
    prefix=options.prefix_path,
  File "c:\users\myjac\appdata\local\programs\python\python36-32\lib\site-packages\pip\req\req_set.py", line 784, in install
    **kwargs
  File "c:\users\myjac\appdata\local\programs\python\python36-32\lib\site-packages\pip\req\req_install.py", line 878, in install
    spinner=spinner,
  File "c:\users\myjac\appdata\local\programs\python\python36-32\lib\site-packages\pip\utils\__init__.py", line 676, in call_subprocess
    line = console_to_str(proc.stdout.readline())
  File "c:\users\myjac\appdata\local\programs\python\python36-32\lib\site-packages\pip\compat\__init__.py", line 75, in console_to_str
    return s.decode('utf_8')
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xce in position 68: invalid continuation byte

解决方案

看起来是标准输出流的编码不对的缘故。使用chcp命令，更改代码页为65001（UTF-8）再执行pip安装命令即可。

另外提供一些chcp命令的参考:

chcp 65001  就是换成UTF-8代码页
chcp 936 可以换回默认的GBK
chcp 437 是美国英语  

2018.01.05