爲什麼PIP忽略衝突的依賴關係？

Question

如果我創建一個虛擬包 - 這裏的/tmp/example_package/setup.py（注意要求）：

from distutils.core import setup 

setup(name='my_project', 
     description="Just a test project", 
     version="1.0", 
     py_modules=['sample'], 
     install_requires=['requests > 0.12']) 

這裏的/tmp/example_package/sample.py：

import requests 

def get_example(): 
    return requests.get("http://www.example.com") 

現在，我創建的virtualenv：

$ virtualenv /tmp/foobar --distribute -p python2.7 
Running virtualenv with interpreter /usr/bin/python2.7 
New python executable in /tmp/foobar/bin/python2.7 
Also creating executable in /tmp/foobar/bin/python 
Installing distribute.................................................................................................................................................................................................done. 
Installing pip................done. 
$ source /tmp/foobar/bin/activate 

我創建了一個requirements.pip 相互矛盾的要求：

# this requires requests > 0.12: 
file:///tmp/example_package 

# but this conflicts: 
requests==0.9.0 

匹普高興地安裝此：

$ pip install -r requirements.pip                                          [18:40:10] 
Unpacking ./example_package 
    Running setup.py egg_info for package from file:///tmp/example_package 

Downloading/unpacking requests==0.9.0 (from -r requirements.pip (line 3)) 
    Downloading requests-0.9.0.tar.gz (55Kb): 55Kb downloaded 
    Running setup.py egg_info for package requests 

Downloading/unpacking certifi>=0.0.4 (from requests==0.9.0->-r requirements.pip (line 3)) 
    Downloading certifi-0.0.8.tar.gz (118Kb): 118Kb downloaded 
    Running setup.py egg_info for package certifi 

Installing collected packages: requests, my-project, certifi 
    Running setup.py install for requests 

    Running setup.py install for my-project 

    Running setup.py install for certifi 

Successfully installed requests my-project certifi 
Cleaning up... 

爲什麼皮普允許這樣做？我的example_package將無法​​正常工作，因爲它的要求沒有得到滿足。

Answer 1

這是匹的限制。需求文件勝過了軟件包的需求。請參閱https://github.com/pypa/pip/issues/775#issuecomment-12748095

Answer 2

看着它好像就應該所有要求遞歸添加到一個大RequirementSet ...，然後用「複製需求」異常碰撞出畫中畫源...

嗯..你確定你的setup.py是正確的？

Distutils的具有requires關鍵字但不install_requires：其中參考本 http://docs.python.org/2/distutils/setupscript.html#relationships-between-distributions-and-packages

SO答案：
https://stackoverflow.com/a/10686196/202168
https://stackoverflow.com/a/13468644/202168