一个列出所有包的Python程序(你可以把它复制到file requirements.txt):

from pip._internal.utils.misc import get_installed_distributions
print_log = ''
for module in sorted(get_installed_distributions(), key=lambda x: x.key):
    print_log +=  module.key + '~=' + module.version  + '\n'
print(print_log)

输出如下所示:

asn1crypto~=0.24.0
attrs~=18.2.0
automat~=0.7.0
beautifulsoup4~=4.7.1
botocore~=1.12.98

这个答案是为Windows用户准备的。正如在所有其他答案中建议的那样，你可以这样使用语句:

import [type the module name]
print(module.__version__) # module + '.' + double underscore + version + double underscore

但是，有一些模块即使在使用上面的方法后也不打印它们的版本。所以，你可以简单地做:

Open the command prompt. Navigate to the file address/directory by using cd (file address) where you've kept your Python and all supporting modules installed. If you have only one Python interpreter on your system, the PyPI packages are normally visible in the directory/folder: Python → Lib → site-packages. use the command "pip install [module name]" and hit Enter. This will show you a message as "Requirement already satisfied: file address\folder name (with version)". See the screenshot below for example: I had to know the version of a pre-installed module named "Selenium-Screenshot". It correctly showed as 1.5.0:

我自己在一个受到严格限制的服务器环境中工作，不幸的是，这里的解决方案都不适合我。可能没有适合所有情况的全局解决方案，但我找到了一个快速的解决方案，即在脚本中读取pip freeze的终端输出，并将模块标签和版本存储在字典中。

import os
os.system('pip freeze > tmpoutput')
with open('tmpoutput', 'r') as f:
    modules_version = f.read()
  
module_dict = {item.split("==")[0]:item.split("==")[-1] for item in modules_versions.split("\n")}

通过传递模块标签键来检索模块的版本，例如:

>>  module_dict["seaborn"]
'0.9.0'

对于未定义字段__version__的情况:

try:
    from importlib import metadata
except ImportError:
    import importlib_metadata as metadata # python<=3.7

metadata.version("package")

或者，就像之前提到的那样:

import pkg_resources
pkg_resources.get_distribution('package').version

前面的答案没有解决我的问题，但这段代码做到了:

import sys 
for name, module in sorted(sys.modules.items()): 
  if hasattr(module, '__version__'): 
    print name, module.__version__ 

在Python 3中用括号括起来的print:

>>> import celery
>>> print(celery.__version__)
3.1.14