Python - 在 Virtual Env 中安装包

Question

I am trying virtual env for the first time in python. I have Python 3.6 and Python 2.7 installed in my machine. I have installed all the necessary packages in Python 3.6. However, the code that I have seems to be compatible with Python 2.7. Hence I opted for Virtaul Env. But I could not access the packages that i need. I have went through the questions in stack overflow but nothing helped. I have tried following steps:

• Created new project in pycharm
• used the interpreter as Python27
• in command prompt, I went to specific virtual env folder and tried pip install package_name

• showing the error as below

  Fatal Python error: Py_Initialize: unable to load the file system codec File "D:\\Users\\username\\venv_name\\lib\\encodings\\__init__.py", line 123 raise CodecRegistryError,\\ ^ SyntaxError: invalid syntax Current thread 0x0000d85c (most recent call first):

I need either to install packages in the venv or transfer already installed packages into venv.

Thanks

Answer 1

I don't know how to solve your problem, since I don't use pycharm myself, but I can tell you what's causing it.

It seems that you are trying to run Python 2 code under Python 3. The raise expression that fails for you is valid under Python 2, but not under Python 3. Therefore the SyntaxError . So, you are probably using the source files from the virtualenv (see that ...\\venv_name\\... path?), but executing them in Python 3 interpreter.

Answer 2

In order for you to install packages to your virtual environment you need to add it first in PyCharm and use it as your interpreter.

You can add your venv by:

By going to Settings( Ctrl + Alt + s in windows)

Click the ⚙ icon next to project interpreter then choose add.

Browser for your virtual environment.

After that you can now install packages to your virtual env by clicking the ➕ icon.

---

Also you cannot just install packages in your virtual environment by going to its directory, you need to activate it first by:

Windows: c:\\path\\to\\your\\venv\\Scripts\\activate.bat

Linux/Mac: source path/to/your/venv/bin/activate

Answer 3

From another SO post, the issue is PYTHONPATH. Clear it, and you should be able to use 2 and 3.