Python3 pip3無法安裝請求

Question

在我的Ubuntu 16.04桌面上，我安裝了python2.7.12和python3.6.1。

seept@seept:~$ python --version 
Python 2.7.12 
seept@seept:~$ python3 --version 
Python 3.6.1 

而且我還安裝了pip和pip3。 pip是用於python2並且pip3用於python3的嗎？

那麼，爲什麼地獄PIP的兩個版本顯示我：

seept@seept:~$ pip --version 
pip 9.0.1 from /home/seept/.local/lib/python3.5/site-packages (python 3.5) 
seept@seept:~$ pip3 --version 
pip 9.0.1 from /home/seept/.local/lib/python3.5/site-packages (python 3.5) 

爲什麼Python的3.5？

seept@seept:~$ which python 
/usr/bin/python 

seept@seept:~$ which python3 
/usr/local/bin/python3 

seept@seept:~$ which pip 
/home/seept/.local/bin/pip 

seept@seept:~$ which pip3 
/home/seept/.local/bin/pip3 

所以我真正的問題是，我需要模塊'請求'爲python3項目。

當我運行：

seept@seept:~$ sudo pip3 install requests 

這是輸出：

The directory '/home/seept/.cache/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag. 
The directory '/home/seept/.cache/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag. 
**Requirement already satisfied: requests in ./.local/lib/python3.5/site-packages** 

順便說一句，我總是得到這個消息：

You are using pip version 8.1.1, however version 9.0.1 is available. 
You should consider upgrading via the 'pip install --upgrade pip' command. 

所以這個輸出說我使用點校園8.1.1但當我運行pip --version它說我我正在運行版本9.0.1。

對我來說，它看起來像我已經搞砸了，應該重新安裝所有？

Answer 1

你應該用virtualenv運行你的項目。它可以保證您的項目目錄安全並避免與其他版本發生衝突。

轉到您的項目目錄，並只用安裝第一的virtualenv：

pip install virtualenv 

在安裝包中運行這個激活的virtualenv之前：

source venv/bin/activate 

現在你的目錄是安全的，你可以安裝打包在這裏保持安全和獨特的另一個目錄。

希望你能理解我的概念。

謝謝。