python调用pip模块,使用pip_install脚本,在IDE中运行自动记录安装包到requirements文件的代码示例
一个安装包会带出一片依赖,不建议一起捕获,因为有的包会按照平台给依赖,比如有的包在windows系统下会下载win32的包,有这个包的项目在linux上会报错。这也是使用pip list --format=freeze
会出现的问题,它会列出当前操作系统,当前python环境的所有包。
示例1:使用Popen
import datetime
import subprocess
import pip, sys
from pathlib import Path
from typing import List
from io import StringIO, TextIOBase
from pyparsing import Word, nums, Literal, Combinedef write_requirement(installed: str): requirement_path = Path.cwd() / "requirements.txt" if not requirement_path.exists(): with open(str(requirement_path), 'w') as f: pass with open(str(requirement_path), "a+") as f: f.writelines(installed) def parse_install_info(stdout_str: str, package_name: str): dash = Literal("-") version = Combine(Word(nums) + ("." + Word(nums)) * 2) package_expr = Combine(Literal(package_name) + dash + version) res = package_expr.searchString(stdout_str) if len(res) == 0: return "" return res[0][0] def run(package_name: str): cmd_install = [sys.executable, "-m", "pip", "install", package_name] p = subprocess.Popen(cmd_install, stdout=subprocess.PIPE, stderr=subprocess.STDOUT) stdout, stderr = p.communicate() if isinstance(stdout, bytes): stdout = stdout.decode('utf-8') installed = parse_install_info(stdout, package_name) if not installed: print("nothing write") return package_name_end_index = installed.index(package_name) + len(package_name)to_write = installed[0 : package_name_end_index] + "==" + installed[ package_name_end_index + 1:] write_requirement(to_write) if __name__ == "__main__": run(package_name)
示例2:使用pip._internal
模块的内置代码,不过这种不安全,不知道后期pip模块会不会有所修改,不让调用
# 写法1
def install(package): buffer = StringIO() sys.stdout = buffer sys.stderr = sys.stdout if hasattr(pip, 'main'): pip.main(['install', package]) else: pip._internal.main(['install', package]) output = buffer.getvalue() parse_install_info(output) # 还原标准输出 sys.stdout = sys.__stdout__ sys.stderr = sys.__stderr__ print("recover stdout, get content from buffer") print(output)# 略: 和示例一后期处理一样# 写法2,只是将TextIOBase封装成class,另外一种风格而已
class CustomWriter(TextIOBase): def __init__(self): self.content = "" def write(self, text): self.content += textdef install2(package): # 创建一个自定义的输出写入器 custom_writer = CustomWriter() # 保存原来的标准输出 original_stdout = sys.stdout # 重定向标准输出到自定义的写入器 sys.stdout = custom_writer # 在这里执行需要输出的代码 print("Hello, World!") print("This is a test.") # 还原标准输出 sys.stdout = original_stdout installed = parse_install_info(custom_writer.content, package_name) # 略: 和示例一后期处理一样