本想用安装一个 requests 库，发现安装报错了。看报错日志感觉是连接它的 pypi 库下载官网有问题，使用默认的 pip 库下载地址安装本来就很慢。
我就试了试，改了个阿里云的镜像地址，然后就好了，速度也变快了。
pip安装python库秒速下载：更改pip数据源。阿里云国外镜像。
报错信息：
C:\Users\Administrator>pip install requests
WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status
=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.con
nection.VerifiedHTTPSConnection object at 0x0354AE90>: Failed to establish a newconnection: [WinError 10061] 由于目标计算机积极拒绝，无法连接。',)': /simple/re
quests/
WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status
=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.con
nection.VerifiedHTTPSConnection object at 0x03563D70>: Failed to establish a newconnection: [WinError 10061] 由于目标计算机积极拒绝，无法连接。',)': /simple/re
quests/
WARNING: Retrying (Retry(total=2, connect=None, read=None, redirect=None, status
=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.con
nection.VerifiedHTTPSConnection object at 0x03563F30>: Failed to establish a newconnection: [WinError 10061] 由于目标计算机积极拒绝，无法连接。',)': /simple/re
quests/
WARNING: Retrying (Retry(total=1, connect=None, read=None, redirect=None, status
=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.con
nection.VerifiedHTTPSConnection object at 0x03563A30>: Failed to establish a newconnection: [WinError 10061] 由于目标计算机积极拒绝，无法连接。',)': /simple/re
quests/
WARNING: Retrying (Retry(total=0, connect=None, read=None, redirect=None, status
=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.con
nection.VerifiedHTTPSConnection object at 0x03563950>: Failed to establish a newconnection: [WinError 10061] 由于目标计算机积极拒绝，无法连接。',)': /simple/re
quests/
ERROR: Could not find a version that satisfies the requirement requests (from ve
rsions: none)
ERROR: No matching distribution found for requests
改完镜像后的效果图：
C:\Users\Administrator>pip install requests
Looking in indexes: https://mirrors.aliyun.com/pypi/simple/
Collecting requestsDownloading https://mirrors.aliyun.com/pypi/packages/51/bd/23c926cd341ea6b7dd0
b2a00aba99ae0f828be89d72b2190f27c11d4b7fb/requests-2.22.0-py2.py3-none-any.whl (
57kB)|█████████████████ | 30kB 2.0MB/s eta 0:00:0|██████████████████████▌ | 40kB 2.7MB/s eta|████████████████████████████ | 51kB 3.4MB/s|████████████████████████████████| 61kB 4.1
MB/s
Collecting certifi>=2017.4.17Downloading https://mirrors.aliyun.com/pypi/packages/b9/63/df50cac98ea0d5b006c
55a399c3bf1db9da7b5a24de7890bc9cfd5dd9e99/certifi-2019.11.28-py2.py3-none-any.wh
l (156kB)|█████████████████ | 81kB 5.5MB/s eta 0:00:0|███████████████████ | 92kB 6.1MB/s eta 0:00|█████████████████████ | 102kB 6.8MB/s eta 0|███████████████████████ | 112kB 6.8MB/s eta|█████████████████████████ | 122kB 6.8MB/s e|███████████████████████████ | 133kB 6.8MB/s|█████████████████████████████▌ | 143kB 6.8M|███████████████████████████████▌| 153kB 6.|████████████████████████████████| 163kB 6.
8MB/s
Collecting chardet<3.1.0,>=3.0.2Downloading https://mirrors.aliyun.com/pypi/packages/bc/a9/01ffebfb562e4274b64
87b4bb1ddec7ca55ec7510b22e4c51f14098443b8/chardet-3.0.4-py2.py3-none-any.whl (13
3kB)|████████████████████████▌ | 102kB 6.8MB/s e|███████████████████████████ | 112kB 6.8MB/s|█████████████████████████████▌ | 122kB 6.8M|████████████████████████████████| 133kB 6.|████████████████████████████████| 143kB 6.
8MB/s
Collecting idna<2.9,>=2.5Downloading https://mirrors.aliyun.com/pypi/packages/14/2c/cd551d81dbe15200be1
cf41cd03869a46fe7226e7450af7a6545bfc474c9/idna-2.8-py2.py3-none-any.whl (58kB)|████████████████████████████████| 61kB ...Requirement already satisfied: urllib3!=1.25.0,!=1.25.1,<1.26,>=1.21.1 in d:\pyt
hon\lib\site-packages (from requests) (1.25.3)
Installing collected packages: certifi, chardet, idna, requests
Successfully installed certifi-2019.11.28 chardet-3.0.4 idna-2.8 requests-2.22.0
喜欢的点个赞?吧！