1. How to install related packages using pip
- pip install package==1.8.0 # specified version
- pip install Package The latest stable version
- pip install package name >= 1.4 # Minimum version that meets the criteria
- pip list --outdated
- pip install --upgrade package # update package
- pip install --upgrade -i https://pypi.doubanio.com/simple/ package 6550
- Source changeover-i,--index-url
2.Requirements file
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requirements contain packages that need to be installed through pip:
pip install -r requirements.txt -
Four common methods of requirements:
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Backup and restore the package environment through pip freeze.
pip freeze > requirements.txt pip install -r requirements.txt PS C:\Users\xiaodong> python -m pip freeze > F:\requirements.txt - Mandatory resolution of dependency problems (not really solving dependency problems).
- Force the use of alternate versions of child dependencies.
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The Constranints file is similar to requirements, but it does not specify the version that must be installed, but constrains the installed version.
pip install -c constranints.txt
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3. Installation with Wheel
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Wheel is a packaged program that has been built. Using Wheel packages to install third-party packages can greatly speed up the installation and reduce the difficulty of installation.
pip install package-1.0-py2.py3-none-any.whl- Note: The file name of the wheel package cannot be changed by itself.
4. unloading package
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Description: When pip updates a package, it will automatically start uninstalling and install a new version.
pip uninstall package
5. packets of information
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View a list of all installed packages
pip list -
View all expired packages and display the latest current version
pip list --outdated -
Packet details
pip show package_name -
Online Search Pack
pip search "pkg" #Search starts with PyPI by default
6.VirtualEnv - Virtual Environment Building (linux System)
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Install virtualenv Library
pip install -i https://pypi.douban.com/simple/ virtualenv -
Creating virtual environment Python 2_env
Virtualenv python2_env #python2_env is a directory to create a virtual environment -
Activating Virtual Environment
source python2_env/bin/activate -
Withdrawal from virtual environment (inactivation)
deactivate -
Specify a specific Python version
Virtualenv -p python2 python2_env
7.requests -- Universal Request Library
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Install requests
sudo pip install -i https://pypi.douban.com/simple/ requests -
Construct request
import requests URL = 'http://fanyi.youdao.com/translate? smartresult=dict&smartresult=rule&smartresult=ugc&sessionFrom=null' headers = { 'User-Agent':'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36', 'X-Requested-With':'XMLHttpRequest' } data = { 'type':'AUTO', 'i':'Come on'.encode('utf-8'), 'doctype':'json', 'xmlVersion':'1.8', 'keyfrom':'fanyi.web', 'ue':'UTF-8', 'action':'FY_BY_CLICKBUTTON', 'typoResult':'true' } r = requests.post(URL,headers=headers,data=data) -
Response object
>>> r <Response [200]>#200 is a status code that indicates the normal response of http requests >>> r.content.split()#split removes spaces [b'{"type":"ZH_CN2EN","errorCode":0,"elapsedTime":0,"translateResult":[[{"src":"\xe5\x8a\xa0\xe6\xb2\xb9","tgt":"Come', b'on"}]],"smartResult":{"type":1,"entries":["","refuel","cheer","play', b'up"]}}'] >>>
8.JSON - JavaScript Object Markup
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Examples of json data
'{"type":"ZH_CN2EN", "errorCode":0, "elapsedTime":0, "translateResult":[[{"src":"\xe5\x8a\xa0\xe6\xb2\xb9","tgt":"Come', b'on"}]], "smartResult":{"type":1,"entries":["","refuel","cheer","play', b'up"]}}' -
Convert json string to Python data
import json-
Direct Conversion String
json.loads() -
String in conversion file
json.load()
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Convert Python data into json strings
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Converting Python data types to Json strings
json.dumps() -
Converting Python data types to files containing Json strings
json.dump()
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Build your own development environment in Linux: Take tornado and sqlalchemy as examples
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1. Create a separate project path
xiaodong@Xiaodong-VMSrv:~/work/tornado_test/xiaodong1$
xiaodong@Xiaodong-VMSrv:~$ mkdir work xiaodong@Xiaodong-VMSrv:~$ cd work/ xiaodong@Xiaodong-VMSrv:~/work$ ls xiaodong@Xiaodong-VMSrv:~/work$ mkdir tornado_test xiaodong@Xiaodong-VMSrv:~/work$ ls tornado_test xiaodong@Xiaodong-VMSrv:~/work$ cd tornado_test/ xiaodong@Xiaodong-VMSrv:~/work/tornado_test$ ls xiaodong@Xiaodong-VMSrv:~/work/tornado_test$ mkdir xiaodong1 xiaodong@Xiaodong-VMSrv:~/work/tornado_test$ ls xiaodong1 - 2. Install Virtualenv Library
xiaodong@Xiaodong-VMSrv:~$ pip install -i https://pypi.douban.com/simple/ virtualenv Collecting virtualenv Downloading https://pypi.doubanio.com/packages/6f/..../virtualenv-15.1.0-py2.py3-none-any.whl (1.8MB) 100% |████████████████████████████████| 1.8MB 3.4MB/s Installing collected packages: virtualenv Successfully installed virtualenv-15.1.0 -
3. Create a virtual environment in this path
xiaodong@Xiaodong-VMSrv:~/work/tornado_test/xiaodong1$ ls xiaodong@Xiaodong-VMSrv:~/work/tornado_test/xiaodong1$ virtualenv python2_tornado New python executable in /home/xiaodong/work/tornado_test/xiaodong1/python2_tornado/bin/python Installing setuptools, pip, wheel...done. -
5. Activating Virtual Environment
xiaodong@XiaodongVMSrv:~/work/tornado_test/xiaodong1/python2_tornado$ source bin/activate -
4. Install tornado,sqlarchemy
(python2_tornado) xiaodong@Xiaodong-VMSrv:~/work/tornado_test/xiaodong1/python2_tornado$ pip install tornado Collecting tornado Downloading tornado-4.5.1.tar.gz (483kB) 100% |████████████████████████████████| 491kB 419kB/s ......#Some content is omitted here Successfully installed backports-abc-0.5 certifi-2017.4.17 singledispatch-3.4.0.3 tornado-4.5.1 (python2_tornado) xiaodong@Xiaodong-VMSrv:~/work/tornado_test/xiaodong1/python2_tornado$ pip install sqlalchemy Collecting sqlalchemy ......#Some content is omitted here Downloading SQLAlchemy-1.1.9.tar.gz (5.2MB) 100% |████████████████████████████████| 5.2MB 47kB/s ...... Successfully built sqlalchemy Installing collected packages: sqlalchemy Successfully installed sqlalchemy-1.1.9