[Linux] Ubuntu install pip and its various bug solutions

Original article http://blog.csdn.net/humanking7/https://blog.csdn.net/humanking7/article/details/84392790

Article Directory###

• surroundings

• 1. Install pip
• 2. View pip version
• 3. Update pip

• 3.1. Normal update

• 3.2. Can't update, install and update through source code

• 3.2.1 Download source code

• 3.2.2 Unzip and install

• 3.2.3 I updated to the latest version, but I get the error ImportError: cannot import name main

• 4. Uninstall pip
• 5. pip commonly used commands

surroundings#

• Configuration environment: ubuntu 16.04
• For the environment: python2.7.12

1. Install pip

apt-get install python-pip

# Of course you can install other things together
apt-get install python-pip python-dev build-essential

2. View pip version#

# Capital V, or--version
pip -V 
# Output:
# pip 8.1.1from/usr/lib/python2.7/dist-packages(python 2.7)

3. Update pip

3.1. Normal update##

pip install --upgrade pip
# or
pip install -U pip

But it may not be able to upgrade, it shows:

root@qfx-HP-xw4600-Workstation:~# pip install -U pip
Collecting pip
 Using cached https://files.pythonhosted.org/packages/c2/d7/90f34cb0d83a6c5631cf71dfe64cc1054598c843a92b400e55675cc2ac37/pip-18.1-py2.py3-none-any.whl
Installing collected packages: pip
 Found existing installation: pip 8.1.1
 Not uninstalling pip at /usr/lib/python2.7/dist-packages, outside environment /usr
Successfully installed pip-8.1.1
You are using pip version 8.1.1, however version 18.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.

3.2. Can't update, install and update through source code##

I have tried various methods, such as using the command: python -m pip install --upgrade pip to install, but the above prompt will still appear, so use the source code to upgrade.

3.2.1 Download source code###

Download the source code, or go to the official website of pip to download https://pypi.org/project/pip/#files

wget https://files.pythonhosted.org/packages/45/ae/8a0ad77defb7cc903f09e551d88b443304a9bd6e6f124e75c0fbbf6de8f7/pip-18.1.tar.gz
# ==========
# Detailed installation information
root@qfx-HP-xw4600-Workstation:~# mkdir pipDir
root@qfx-HP-xw4600-Workstation:~# cd pipDir/
root@qfx-HP-xw4600-Workstation:~/pipDir# wget https://files.pythonhosted.org/packages/45/ae/8a0ad77defb7cc903f09e551d88b443304a9bd6e6f124e75c0fbbf6de8f7/pip-18.1.tar.gz
- - 2018- 11- 2313:56:53- - https://files.pythonhosted.org/packages/45/ae/8a0ad77defb7cc903f09e551d88b443304a9bd6e6f124e75c0fbbf6de8f7/pip-18.1.tar.gz
Parsing host files.pythonhosted.org(files.pythonhosted.org)... 2a04:4e42:1a::319,151.101.109.63
Connecting files.pythonhosted.org(files.pythonhosted.org)|2a04:4e42:1a::319|:443...connected.
HTTP request has been sent, waiting for response...200 OK
Length: 1259370(1.2M)[binary/octet-stream]
Saving to: “pip-18.1.tar.gz”

pip-18.1.tar.gz           100%[====================================>]1.20M  9.92KB/s    in 2m 35s  

2018- 11- 2313:59:31(7.94 KB/s)-Saved "pip-18.1.tar.gz” [1259370/1259370])

root@qfx-HP-xw4600-Workstation:~/pipDir# ls
pip-18.1.tar.gz

3.2.2 Unzip and install###

Unzip and install

# Unzip
root@qfx-HP-xw4600-Workstation:~/pipDir# tar xzvf pip-18.1.tar.gz 
# View the unzipped directory
root@qfx-HP-xw4600-Workstation:~/pipDir# ls
pip-18.1  pip-18.1.tar.gz
# Enter the directory to view the files inside
root@qfx-HP-xw4600-Workstation:~/pipDir# cd pip-18.1/
root@qfx-HP-xw4600-Workstation:~/pipDir/pip-18.1# ls -1
AUTHORS.txt
docs
LICENSE.txt
MANIFEST.in
NEWS.rst
PKG-INFO
pyproject.toml
README.rst
setup.cfg
setup.py
src
# Install pip
root@qfx-HP-xw4600-Workstation:~/pipDir/pip-18.1# python setup.py install
......

Installed /usr/local/lib/python2.7/dist-packages/pip-18.1-py2.7.egg
Processing dependencies for pip==18.1
Finished processing dependencies for pip==18.1
# This means the installation was successful

3.2.3 I updated to the latest version, but I get an error ImportError: cannot import name main

Use pip -V to check the version and find an error:

root@qfx-HP-xw4600-Workstation:~/pipDir/pip-18.1# pip -V
Traceback(most recent call last):
 File "/usr/bin/pip", line 9,in<module>from pip import main
ImportError: cannot import name main

The reason for the problem:
It is said to be a bug. As long as you use pip, an exception will be thrown, but it is easier to solve.

First locate the problem:
The problem occurs in the pip file in /usr/bin/, open it with vim and edit it:
Original code:

#! /usr/bin/python
# GENERATED BY DEBIAN

import sys 

# Run the main entry point, similarly to how setuptools does it, but because
# we didn't install the actual entry point from setup.py, don't use the
# pkg_resources API.from pip import main
if __name__ =='__main__':
 sys.exit(main())

Modified code:

#! /usr/bin/python
# GENERATED BY DEBIAN

import sys 

# Run the main entry point, similarly to how setuptools does it, but because
# we didn't install the actual entry point from setup.py, don't use the
# pkg_resources API.from pip import __main__
# from pip import main
if __name__ =='__main__':
 sys.exit(__main__._main())
 # sys.exit(main())

After saving, check the current version of pip:

root@qfx-HP-xw4600-Workstation:~/pipDir/pip-18.1# pip -V
pip 18.1from/usr/local/lib/python2.7/dist-packages/pip-18.1-py2.7.egg/pip(python 2.7)

ok, it has been successfully updated to pip 18.1.

4. Uninstall pip

apt-get remove python-pip

5. pipCommon Commands#

• View pip help: pip -help
• Install the new python package: pip install packageName
• Uninstall the python package: pip uninstall packageName
• Find the python package: pip search packageName
• Check the pip installation package of python2: pip list
• Check the pip installation package of python3: pip3 list

OK！
Above, Enjoy~