今天用pip的时候突然不能正常使用，在这里简单记录一下。

提示pip版本不对

错误提示

You are using pip version 9.0.3, however version 18.0.1 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.

处理过程

去官网下载最新版的包，直接解压安装即可；

参考来源

Python2.7 自带的 pip9.0 升级到 pip18.0

明确已经安装pip，但是系统提示找不到pip

错误提示

-bash: /home/imoyao/.local/bin/pip: No such file or directory

解决方案

1.which pip 
/usr/local/bin/pip

2.pip 
-su: /usr/bin/pip: No such file or directory

3.type pip 
pip is hashed (/usr/bin/pip) 
So pip is definintely in /usr/local/bin/pip but it is been cached as in /usr/bin/pip, thanks to the Stackoverflow question, the solution is very simple:

4.hash -r 
When the cache is clear, pip is working again.

参考来源

/usr/bin/pip: No such file or directory

安装或升级pip时提示SSLError

错误提示

Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:833)'),)': /simple/pip/
Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:833)'),)': /simple/pip/
Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:833)'),)': /simple/pip/
Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:833)'),)': /simple/pip/
Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:833)'),)': /simple/pip/
Could not fetch URL https://pypi.python.org/simple/pip/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.python.org', port=443): Max retries exceeded with url: /simple/pip/ (Caused by SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:833)'),)) - skipping
#其实本人遇到的错误是
(Caused by SSLError(SSLError(1, u'[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:726)'),))

解决方案

  • 临时方案
安装时添加参数：
--trusted-host pypi.python.org
此方式表示信任该域名，但是每一次安装包的时候都需要该操作，比较麻烦；
  • 永久方案

修改pip.conf 配置文件，该文件在Linux系统中的可能位置：

/etc/pip.conf

~/.pip/pip.conf

~/.config/pip/pip.conf

如果都没有的话，可以手动创建之后添加以下内容：

[global]
index-url = http://mirrors.aliyun.com/pypi/simple/      # 本机使用阿里源代理
[install]
trusted-host=mirrors.aliyun.com

# global字段还看到其他写法：
[global]
trusted-host = pypi.python.org
               pypi.org
               files.pythonhosted.org

参考来源

pip issue installing almost any library
Linux 设置 pip 镜像 Pip Warning：–trusted-host 问题解决方案

安装MySQL-python时提示

错误提示

EnvironmentError: mysql_config not found

解决方案

  • CentOS
yum install libffi-devel 
pip install mysql-connector-python
  • Ubuntu
sudo apt install default-libmysqlclient-dev

参考来源

pip install mysql-python fails with EnvironmentError: mysql_config not found