Python包的安装

Python包的安装#

首先，我们需要安装一下，今天演示所需要的包，正常情况下，以numpy为例，我们可以用以下方式安装包：

在指定环境下，在命令行中输入pip install numpy
在指定环境下，在命令行中输入python -m pip install numpy
或者使用conda安装，在命令行中输入conda install numpy --name [你的环境名称]

请注意，在国内使用上述命令，可能速度较慢，我们建议使用清华源，可以显著提升安装速度：

在jupyter notebook中，提供了更加便捷的方式安装这些包：

!pip install --upgrade pip
!pip config set global.index-url https://pypi.tuna.tsinghua.edu.cn/simple
!pip install numpy matplotlib pandas scikit-learn sympy scipy scikit-opt

Looking in indexes: https://pypi.tuna.tsinghua.edu.cn/simple
Requirement already satisfied: pip in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (23.2.1)

Writing to /home/xuyisen/.config/pip/pip.conf

Looking in indexes: https://pypi.tuna.tsinghua.edu.cn/simple
Requirement already satisfied: numpy in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (1.26.0)
Requirement already satisfied: matplotlib in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (3.8.0)
Requirement already satisfied: pandas in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (2.1.1)
Requirement already satisfied: scikit-learn in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (1.3.1)
Requirement already satisfied: sympy in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (1.12)
Requirement already satisfied: scipy in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (1.11.3)
Requirement already satisfied: scikit-opt in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (0.6.6)
Requirement already satisfied: contourpy>=1.0.1 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from matplotlib) (1.1.1)
Requirement already satisfied: cycler>=0.10 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from matplotlib) (0.12.1)
Requirement already satisfied: fonttools>=4.22.0 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from matplotlib) (4.43.1)
Requirement already satisfied: kiwisolver>=1.0.1 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from matplotlib) (1.4.5)
Requirement already satisfied: packaging>=20.0 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from matplotlib) (23.2)
Requirement already satisfied: pillow>=6.2.0 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from matplotlib) (10.0.1)
Requirement already satisfied: pyparsing>=2.3.1 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from matplotlib) (3.1.1)

Requirement already satisfied: python-dateutil>=2.7 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from matplotlib) (2.8.2)
Requirement already satisfied: pytz>=2020.1 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from pandas) (2023.3.post1)
Requirement already satisfied: tzdata>=2022.1 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from pandas) (2023.3)

Requirement already satisfied: joblib>=1.1.1 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from scikit-learn) (1.3.2)
Requirement already satisfied: threadpoolctl>=2.0.0 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from scikit-learn) (3.2.0)
Requirement already satisfied: mpmath>=0.19 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from sympy) (1.3.0)

Requirement already satisfied: six>=1.5 in /home/xuyisen/anaconda3/envs/JBtest/lib/python3.11/site-packages (from python-dateutil>=2.7->matplotlib) (1.16.0)

在安装完成后，我们需要导入包，才可以使用。我们可以使用import来导入我们需要的包，下面展示了几种import的用法

import math    #导入后，调用时需要加入前缀
print(math.pi)

from math import pi   #可以直接使用pi，不需要前缀
print(pi)

import math as ma   #同第一种，但是使用别名
print(ma.pi)

from math import pi as yzl   #同第二种，但是使用别名
print(yzl)

141592653589793
141592653589793
141592653589793
141592653589793