Matplotlib not installing inside virtualenv mac
Question: So I have Python 3 and `matplotlib` installed globally. If I run python
outside of a virtual environment and import matplotlib to check the version it
shows 1.5.1 . But I am facing problems installing matplotlib within a virtual
environment. I created a virtual environment using the command `python3 -m
venv ds` and activated `ds`. These are the contents of my `requirements.txt`

`matplotlib==1.4.2 numpy==1.9.1`

When I do `pip3 install -r requirements.txt` I get this

    
    
        Collecting matplotlib==1.4.2 (from -r requirements.txt (line 1))
      Using cached matplotlib-1.4.2.tar.gz
        Complete output from command python setup.py egg_info:
        Traceback (most recent call last):
          File "<string>", line 20, in <module>
          File "/private/var/folders/ym/gfrm424x31j4vd944cdhn4hr0000gn/T/pip-build-pcfq8bhb/matplotlib/setup.py", line 155, in <module>
            result = package.check()
          File "/private/var/folders/ym/gfrm424x31j4vd944cdhn4hr0000gn/T/pip-build-pcfq8bhb/matplotlib/setupext.py", line 962, in check
            min_version='2.3', version=version)
          File "/private/var/folders/ym/gfrm424x31j4vd944cdhn4hr0000gn/T/pip-build-pcfq8bhb/matplotlib/setupext.py", line 446, in _check_for_pkg_config
            if (not is_min_version(version, min_version)):
          File "/private/var/folders/ym/gfrm424x31j4vd944cdhn4hr0000gn/T/pip-build-pcfq8bhb/matplotlib/setupext.py", line 174, in is_min_version
            return found_version >= expected_version
          File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/distutils/version.py", line 70, in __ge__
            c = self._cmp(other)
          File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/distutils/version.py", line 337, in _cmp
            if self.version < other.version:
        TypeError: unorderable types: str() < int()
        IMPORTANT WARNING:
            pkg-config is not installed.
            matplotlib may not be able to find some of its dependencies
        ============================================================================
        Edit setup.cfg to change the build options
    
        BUILDING MATPLOTLIB
                    matplotlib: yes [1.4.2]
                        python: yes [3.5.1 (v3.5.1:37a07cee5969, Dec  5 2015,
                                21:12:44)  [GCC 4.2.1 (Apple Inc. build 5666) (dot
                                3)]]
                      platform: yes [darwin]
    
        REQUIRED DEPENDENCIES AND EXTENSIONS
                         numpy: yes [version 1.10.4]
                           six: yes [using six version 1.10.0]
                      dateutil: yes [dateutil was not found. It is required for date
                                axis support. pip/easy_install may attempt to
                                install it after matplotlib.]
                          pytz: yes [pytz was not found. pip will attempt to install
                                it after matplotlib.]
                       tornado: yes [tornado was not found. It is required for the
                                WebAgg backend. pip/easy_install may attempt to
                                install it after matplotlib.]
                     pyparsing: yes [pyparsing was not found. It is required for
                                mathtext support. pip/easy_install may attempt to
                                install it after matplotlib.]
                         pycxx: yes [Official versions of PyCXX are not compatible
                                with matplotlib on Python 3.x, since they lack
                                support for the buffer object.  Using local copy]
                        libagg: yes [pkg-config information for 'libagg' could not
                                be found. Using local copy.]
    
        ----------------------------------------
    Command "python setup.py egg_info" failed with error code 1 in /private/var/folders/ym/gfrm424x31j4vd944cdhn4hr0000gn/T/pip-build-pcfq8bhb/matplotlib
    You are using pip version 7.1.2, however version 8.0.2 is available.
    You should consider upgrading via the 'pip install --upgrade pip' command.
    

How should I install matplotlib version 1.4.2 in virtual environment ?

My question has been marked as duplicate but that link doesn't solve my
question. The solution given is for Ubuntu


Answer: You can use the system package in your virtualenv with
[this](http://virtualenv.readthedocs.org/en/latest/userguide.html#the-system-
site-packages-option) option.

Otherwise, [this SO
post](http://stackoverflow.com/questions/27024731/matplotlib-compilation-
error-typeerror-unorderable-types-str-int) may help you.

