在安装mechanize后，我似乎无法导入它。
我已经尝试从pip、easy_install和通过python setup.py从这个repo安装:https://github.com/abielr/mechanize。所有这些都无济于事，因为每次我输入Python交互时，我得到:
Python 2.7.3 (default, Aug 1 2012, 05:14:39)
[GCC 4.6.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import mechanize
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: No module named mechanize
>>>
我之前运行的安装报告已经成功完成，因此我希望导入能够正常工作。是什么导致了这个错误?
当前回答
今天，我发现setup.py包也会产生这个问题。
我有一个分类器< 3的设置
setup(
name='data_reader',
version='0.1',
description='data_reader by Mithril ',
long_description=long_description,
author='Mithril',
classifiers=[
'Development Status :: 1 - Beta',
'Programming Language :: Python :: 2',
'Programming Language :: Python :: 2.6',
'Programming Language :: Python :: 2.7',
'Intended Audience :: Developers',
'Operating System :: OS Independent',
"License :: GPLv3",
'Topic :: Internet :: WWW/HTTP',
'Topic :: Software Development :: Libraries :: Tools',
'Topic :: Software Development :: Libraries :: Python Modules',
],
)
我在conda env中使用python 3.7，我发现
pip install .
# or
pip install git+https://github.com/eromoe/data_reader
全部成功，但导入data_reader raise未找到。
经过一些测试，挖掘后只改变分类器
classifiers=[
'Development Status :: 1 - Beta',
"Programming Language :: Python :: 3",
'Intended Audience :: Developers',
'Operating System :: OS Independent',
"License :: GPLv3",
'Topic :: Internet :: WWW/HTTP',
'Topic :: Software Development :: Libraries :: Tools',
'Topic :: Software Development :: Libraries :: Python Modules',
],
重新安装，导入恢复正常!
其他回答
在我的情况下(WIN10主机上的Ubuntu 20.04虚拟机)，我有一个混乱的情况，安装了许多版本的Python和不同点的共享库(在文件系统的许多点安装pip)。我指的是3.8.10 Python版本。 经过多次测试，我用谷歌搜索发现了一个建议(但是“对不起，我没有链接”)。下面是我为解决这个问题所做的:
From shell session on Ubuntu 20.04 VM, (inside the Home, in my case /home/hduser), I've started a Jupyter Notebook session with the command "jupyter notebook". Then, when jupyter was running I've opened a .ipynb file to give commands. First : pip list --> give me the list of packages installed, and, sympy wasn't present (although I had installed it with "sudo pip install sympy" command. Last with the command !pip3 install sympy (inside jupyter notebook session) I've solved the problem, here the screen-shot : Now, with !pip list the package "sympy" is present, and working :
Python导入机制确实有效，所以:
你的PYTHONPATH是错误的， 您的库没有安装在您认为的位置 您有另一个具有相同名称的库来掩盖这个库
当您通过easy_install或pip安装时，它是否成功完成?全输出是多少?您正在使用哪个python安装?如果您正在将模块安装到系统目录(如果您正在使用系统python安装)，则可能需要在使用安装命令之前使用sudo。你的问题中没有太多有用的信息，但是一些工具可能会有帮助，包括:
echo $PYTHONPATH and/or echo $PATH: when importing modules, Python searches one of these environment variables (lists of directories, : delimited) for the module you want. Importing problems are often due to the right directory being absent from these lists which python, which pip, or which easy_install: these will tell you the location of each executable. It may help to know. Use virtualenv, like @JesseBriggs suggests. It works very well with pip to help you isolate and manage the modules and environment for separate Python projects.
我在系统上安装2.7和3.5时遇到了这个问题，试图用Python-Telegram-Bot测试电报机器人。
在使用pip和pip3安装后，无论是否使用sudo，我都无法让它工作。我总是得到:
Traceback (most recent call last):
File "telegram.py", line 2, in <module>
from telegram.ext import Updater
File "$USER/telegram.py", line 2, in <module>
from telegram.ext import Updater
ImportError: No module named 'telegram.ext'; 'telegram' is not a package
正确地读取错误消息告诉我，python正在当前目录中查找telegram.py。我有一个脚本叫telegram。py当我调用import时，它被python加载了。
总结，确保在尝试导入时，当前工作目录中没有任何package.py。(并仔细阅读错误消息)。
我无法让PYTHONPATH正常工作。我意识到添加export修复了这个问题:
(工作)
export PYTHONPATH=$PYTHONPATH:~/test/site-packages
vs.
(没有工作)
PYTHONPATH=$PYTHONPATH:~/test/site-packages
