I get some error and problems when install "matplotlib"

Question

I have get a virtual env on '/home/name/pyenv' for python2.7.9; Now I want to install 'matplotlib' for it; then I activate this virtual env and install 'matplotlib' as below:

• by command "sudo apt-get install python-matplotlib"; (if delete "sudo", permission denied), it runs well and I find "matplotlib" is exactly installed, but it is for default python and not for virtual env(pyenv) ;

• by command "pip install matplotlib"

  I get error as below:

                  * The following required packages can not be built:
  
                  * freetype
  

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Cleaning up... Command python setup.py egg_info failed with error code 1 in /tmp/pip-build-tYCFkL/matplotlib Exception information: Traceback (most recent call last): File "/home/caofa/odoo-9.0/local/lib/python2.7/site-packages/pip/basecommand.py", line 122, in main status = self.run(options, args) File "/home/caofa/odoo-9.0/local/lib/python2.7/site-packages/pip/commands/install.py", line 290, in run requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle) File "/home/caofa/odoo-9.0/local/lib/python2.7/site-packages/pip/req.py", line 1230, in prepare_files req_to_install.run_egg_info() File "/home/caofa/odoo-9.0/local/lib/python2.7/site-packages/pip/req.py", line 326, in run_egg_info command_desc='python setup.py egg_info') File "/home/caofa/odoo-9.0/local/lib/python2.7/site-packages/pip/util.py", line 716, in call_subprocess % (command_desc, proc.returncode, cwd)) InstallationError: Command python setup.py egg_info failed with error code 1 in /tmp/pip-build-tYCFkL/matplotlib

I want to install it by method 1, but i don;t know how to install it for virtual env.

Answer 1

when working in venv then try to used pip for installation for python packages ,sudo apt-get install normally using for root user of Linux. for your case you could try pip install matplotlib==2.2.5

Answer 2

One possibility is to install matplotlib globally then create your virtualenv with the site packages, see here for someone with exactly the same problem, by using virtualenv --system-site-packages you can then activate your virtualenv and add additional packages, or update them, within your virtualenv only.

I am reasonably sure that you can even uninstall globally installed packages within your virtualenv without impacting your global installation but suggest you pick a small package that you can easily reinstall to test this on early on.