Install pycairo in virtualenv

问题:

I've tried to install pycairo in a virtualenv to use in a Django project. I've ran the pip install pycairo==1.10.0 command which finds the package and downloads it unlike other commands like pip install pycairo, etc. but when starting to install the package it throws an error.

Here's the log:

Downloading/unpacking pycairo==1.10.0
  Running setup.py egg_info for package pycairo
    Traceback (most recent call last):
      File "<string>", line 14, in <module>
    IOError: [Errno 2] No such file or directory:
'/home/radu/Desktop/djangos/workout/venv/build/pycairo/setup.py'
Complete output from command python setup.py egg_info:
Traceback (most recent call last):

File "<string>", line 14, in <module>

IOError: [Errno 2] No such file or directory:
'/home/radu/Desktop/djangos/workout/venv/build/pycairo/setup.py'

----------------------------------------
Command python setup.py egg_info failed with error code 1 in 
/home/radu/Desktop/djangos/workout/venv/build/pycairo
Storing complete log in /home/radu/.pip/pip.log

Could you please give me any hints about what to do? Should I try and write a setup.py file for the package and then try to install it? (i'm not sure it's even a solution, i still am trying to figure out what I can do).

Thanks in advance!

回答1:

Good news, everyone!

I just released cairocffi: http://packages.python.org/cairocffi/

It’s a replacement for pycairo that installs with pip in a virtualenv, runs on Python 2 and 3, as well as PyPy.

pip install cairocffi

In your code:

import cairocffi as cairo
# Enjoy the same API as Pycairo.

Feedback welcome. (Although the issue tracker might be a better channel than here.)

回答2:

Although py2cairo doesn't install nicely using pip, you can still install py2cairo into the virtual environment using the build instructions in the INSTALL file from the distribution.

You will need the cairo-dev/cairo-devel package for you os installed in order to build the package.

Do the following to install into your virtual environment:

1. download, unpack, and cd into the the py2cairo directory
2. Activate your virtual environment
3. Follow the standard build procedure

./waf configure --prefix=$VIRTUAL_ENV

./waf build

./waf install

回答3:

pycairo currently does not support installation through pip/distutils. The project’s install docs instructs to use either waf or autotools.

To use pycairo in a virtualenv, you need to:

• Install pycairo system-wide, preferably through your distribution’s packages
• Then, either:
  1. Create a virtualenv with the --system-site-packages option or remove the lib/pythonX.Y/no-global-site-packages.txt file after the fact.
  2. Or add a symbolic link to the cairo package (the directory containing _cairo.so). Something like this:

     ln -s /usr/lib/python2.7/site-packages/cairo ./venv/lib/python2.7/site-packages
     

Of course 1. has the downside that you will not profit from virtualenv’s isolation from other packages installed system-wide.

回答4:

For anyone trying to use pycairo (for Python 2.7) in conjunction with Homebrew and virtualenv --no-site-packages ... this Worked For Me:

1. brew install py2cairo

2. Then, find the path where Homebrew installed it to, will be something like:

   ls -l /usr/local/lib/python2.7/site-packages/cairo/
   total 24
   lrwxr-xr-x  1 anentropic  admin   80 10 Jun 14:26 __init__.py -> ../../../../Cellar/py2cairo/1.10.0/lib/python2.7/site-packages/cairo/__init__.py
   lrwxr-xr-x  1 anentropic  admin   78 10 Jun 14:26 _cairo.so -> ../../../../Cellar/py2cairo/1.10.0/lib/python2.7/site-packages/cairo/_cairo.so
   

3. You want to find the path at the base of those symlinks, something like:
   /usr/local/Cellar/py2cairo/1.10.0/lib/python2.7/site-packages

4. Then create a .pth file in your virtualenv site packages:
   echo "/usr/local/Cellar/py2cairo/1.10.0/lib/python2.7/site-packages" > venv/lib/python2.7/site-packages/cairo.pth

(may want to deactivate and re-activate your virtualenv for good luck, not sure)

回答5:

If cairocffi installation in virtualenv does not work and python-dev libffi-dev are unavailable (ArchLinux) setting environmental variable PKG_CONFIG_PATH=/usr/lib/libffi-3.2.1/include works.

回答6:

If you are using Homebrew you can install the pycario (Python 3+) and py2cario (Python 2.6-2.7) recipes:

brew install pycario