话不多说直接上代码

import os
from PyQt5.QtWidgets import QWidget, QApplication, QComboBox, QPushButton
import sys


class Window(QWidget):
    def __init__(self):
        super().__init__()
        self.setup_ui()

    def setup_ui(self):
        self.resize(500, 100)
        self.setWindowTitle("更改pip源")
        # 实例化QComBox对象
        self.cb = QComboBox(self)
        self.cb.resize(320, 30)
        self.cb.move(90, 10)
        # 添加条目
        self.cb.addItems(["清华镜像源", "阿里巴巴镜像源", "豆瓣镜像源", "中国科技大学镜像源", "山东理工大学镜像源", "华中理工大学镜像源"])
        # 信号
        # print(self.cb.currentText())
        self.cb.index = 0
        # 返回选中项文本
        # print(self.cb.currentIndex())
        # 返回选中项索引
        self.cb.currentIndexChanged.connect(self.print_v)  # 条目发生改变，发射信号，传递条目索引
        # 清华索引0，阿里索引1,豆瓣索引2，中国科技大学3，山东理工大学4, 华中理工大学5
        # 添加按钮
        self.submit = QPushButton(self)
        self.submit.setText("修改")
        self.submit.resize(320, 30)
        self.submit.move(90, 50)
        self.submit.clicked.connect(self.write_ini)
        self.submit.show()
        self.show()

    def print_v(self, i):
        print(self.cb.currentText())
        # print(i)
        self.cb.index = i

    def write_ini(self):
        # print(self.cb.currentIndex())
        # 返回选中项索引
        index = self.cb.index
        if index == 0:
            source = "https://pypi.tuna.tsinghua.edu.cn/simple"
            source_trusted = "pypi.tuna.tsinghua.edu.cn"
            # 清华镜像源
        elif index == 1:
            source = "http://mirrors.aliyun.com/pypi/simple/"
            source_trusted = "mirrors.aliyun.com"
            # 阿里镜像源
        elif index == 2:
            source = "http://pypi.douban.com/simple/"
            source_trusted = "pypi.douban.com"
            # 豆瓣镜像源
        elif index == 3:
            source = "http://pypi.mirrors.ustc.edu.cn/simple/"
            source_trusted = "pypi.mirrors.ustc.edu.cn"
            # 中国科学技术大学镜像源
        elif index == 4:
            source = "http://pypi.sdutlinux.org/simple/"
            source_trusted = "pypi.sdutlinux.org"
            # 山东理工大学镜像源
        elif index == 5:
            source = "http://pypi.hustunique.com/simple/"
            source_trusted = "pypi.hustunique.com"
            # 华中理工大学镜像源
        config = "[global]\nindex-url = " + source + "\n[install]\ntrusted-host=" + source_trusted
        pip_path = os.environ["USERPROFILE"] + "\\pip\\"
        if not os.path.exists(pip_path):
            os.makedirs(pip_path)
        with open(pip_path + "pip.ini", "w+") as f:
            f.write(config)


if __name__ == "__main__":
    app = QApplication(sys.argv)
    win_root = Window()
    sys.exit(app.exec_())

pip换源app 实现