如果通过本地文件夹中的循环安装 python 包，则会出错

Question

我正在尝试使用循环通过 python 代码安装一些包，但一次只能安装一个包。

在下一个包中出现以下错误。

Could not install packages due to an EnvironmentError: [Errno 2] No such file or directory: 'c:\\users\\akshay~1.sha\\appdata\\local\\temp\\pip-req-tracker-aoybzz\\f37aad13bd20c8b1e66a004a7c01edf203f7e46ba784c9954fe935f7'

如果我再次运行脚本，它将安装第二个包并为第三个包抛出错误。如果我第三次运行它会安装第三次，我想一次性安装所有的包，请帮忙。下面是代码

================================================ ==============================

import os

from pip._internal import main as pipmain

PACKAGES = {'pymongo': 'pymongo-3.4.0', 'pexpect': 'pexpect-4.6.0', 'pathlib': 'pathlib-1.0.1'}

def install_dependency(pkg_name, crnt_path):
    pkg_path = os.path.join(crnt_path, "dependencies\\"+pkg_name+"\\")
    print("Installing package from local...", pkg_name)
    pipmain(["install", pkg_path])

def check_dependecies():
    current_path = os.path.dirname(os.path.abspath(__file__))
    print(PACKAGES.keys())
    for package_name in PACKAGES.keys():
        try:
            __import__(package_name, globals=globals())
            print("================> Package imported successfully", package_name)
        except ImportError as import_error:
            print("Package not present", import_error)
            install_dependency(PACKAGES[package_name], current_path)
            print("================> Package imported successfully", package_name)
            __import__(package_name, globals=globals())

if __name__ == "__main__":
    check_dependecies()

Answer 1

我遇到了同样的问题，我已经使用解决方法解决了这个问题。

我们知道我们不能使用 pip 在 for 循环中安装多个包，但我们也知道我们可以一次安装多个包！

我就是这样继续的：

1. 循环通过我们的包寻找它们的存在，如果没有，我们将它们保存在一个字典中{pkg_name: pkg_id}（例如：{'pymongo': 'pymongo-3.4.0'}）
2. 创建仅由pkg_id 组成的列表pkg2install（例如：['pymongo-3.4.0', 'pexpect-4.6.0']）
3. 使用pipmain 一次性安装它们：`pipmain(['install', *pkg2install])

您的代码已审核：

from pip._internal import main as pipmain

PACKAGES = {'pymongo': 'pymongo', 'pexpect': 'pexpect', 'pathlib': 'pathlib'}


def check_dependecies():
    missing_pkgs = {}

    for package_name in PACKAGES.keys():
        try:
            __import__(package_name, globals=globals())
            print("================> Package imported successfully", package_name)

        except ImportError as import_error:
            print("Package not present", import_error)

            missing_pkgs.update({package_name: PACKAGES[package_name]})

    pkgs2install = missing_pkgs.values()

    status = pipmain(["install", *pkgs2install])

    if status == 0:
        print("================> Missing packages installed successfully", pkgs2install)    

        for pkg in missing_pkgs.keys():
            __import__(pkg, globals=globals())
            print("================> Package imported successfully", pkg)


if __name__ == "__main__":
    check_dependecies()

它生成的输出：

Package not present No module named 'pymongo'
Package not present No module named 'pexpect'
================> Package imported successfully pathlib
Collecting pymongo
  Downloading https://files.pythonhosted.org/packages/a3/8c/ec46f4aa95515989711a7893e64c30f9d33c58eaccc01f8f37c4513739a2/pymongo-3.9.0-cp37-cp37m-macosx_10_6_intel.whl (378kB)
    100% |████████████████████████████████| 378kB 4.4MB/s 
Collecting pexpect
  Using cached https://files.pythonhosted.org/packages/0e/3e/377007e3f36ec42f1b84ec322ee12141a9e10d808312e5738f52f80a232c/pexpect-4.7.0-py2.py3-none-any.whl
Collecting ptyprocess>=0.5 (from pexpect)
  Using cached https://files.pythonhosted.org/packages/d1/29/605c2cc68a9992d18dada28206eeada56ea4bd07a239669da41674648b6f/ptyprocess-0.6.0-py2.py3-none-any.whl
Installing collected packages: pymongo, ptyprocess, pexpect
Successfully installed pexpect-4.7.0 ptyprocess-0.6.0 pymongo-3.9.0
================> Missing packages installed successfully dict_values(['pymongo', 'pexpect'])
================> Package imported successfully pymongo
================> Package imported successfully pexpect

注意：我没有使用版本或本地包，但机制应该保持不变

尽管晚了 11 个月，但我希望这对您有所帮助。