How to fix error with freetype while installing all packages from a requirements.txt file?

Question

I ran the following command to install dependencies for a Python project?

# pip install requirements.txt 
Collecting requirements.txt
  Could not find a version that satisfies the requirement requirements.txt (from versions: )
No matching distribution found for requirements.txt

I searched on Google and found this post: python pip trouble installing from requirements.txt but I don't quite understand what the solution was in that post.

Here is my requirements.txt file:

# cat requirements.txt 
ordereddict==1.1
argparse==1.2.1
python-dateutil==2.2
matplotlib==1.3.1
nose==1.3.0
numpy==1.8.0
pymongo==3.3.0
psutil>=2.0

I then tried to do pip3 install -r requirements.txt and here is the output:

# pip3 install -r requirements.txt 
Requirement already satisfied: ordereddict==1.1 in /usr/local/lib/python3.5/dist-packages (from -r requirements.txt (line 1))
Collecting argparse==1.2.1 (from -r requirements.txt (line 2))
  Using cached argparse-1.2.1.tar.gz
Collecting python-dateutil==2.2 (from -r requirements.txt (line 3))
  Using cached python-dateutil-2.2.tar.gz
Collecting matplotlib==1.3.1 (from -r requirements.txt (line 4))
  Using cached matplotlib-1.3.1.tar.gz
    Complete output from command python setup.py egg_info:
    ============================================================================
    Edit setup.cfg to change the build options
    
    BUILDING MATPLOTLIB
                matplotlib: yes [1.3.1]
                    python: yes [3.5.2 (default, Nov 17 2016, 17:05:23)  [GCC
                            5.4.0 20160609]]
                  platform: yes [linux]
    
    REQUIRED DEPENDENCIES AND EXTENSIONS
                     numpy: yes [version 1.11.3]
                  dateutil: yes [using dateutil version 2.6.0]
                   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 [using pyparsing version 2.1.10]
                     pycxx: yes [Official versions of PyCXX are not compatible
                            with Python 3.x.  Using local copy]
                    libagg: yes [pkg-config information for 'libagg' could not
                            be found. Using local copy.]
                  freetype: no  [The C/C++ header for freetype2 (ft2build.h)
                            could not be found.  You may need to install the
                            development package.]
                       png: yes [pkg-config information for 'libpng' could not
                            be found. Using unknown version.]
    
    OPTIONAL SUBPACKAGES
               sample_data: yes [installing]
                  toolkits: yes [installing]
                     tests: yes [using nose version 1.3.7]
    
    OPTIONAL BACKEND EXTENSIONS
                    macosx: no  [Mac OS-X only]
                    qt4agg: no  [PyQt4 not found]
                   gtk3agg: no  [gtk3agg backend does not work on Python 3]
                 gtk3cairo: no  [Requires cairo to be installed.]
                    gtkagg: no  [Requires pygtk]
                     tkagg: no  [TKAgg requires Tkinter.]
                     wxagg: no  [requires wxPython]
                       gtk: no  [Requires pygtk]
                       agg: yes [installing]
                     cairo: no  [cairo not found]
                 windowing: no  [Microsoft Windows only]
    
    OPTIONAL LATEX DEPENDENCIES
                    dvipng: no
               ghostscript: no
                     latex: no
                   pdftops: no
    
    ============================================================================
                            * The following required packages can not be built:
                            * freetype
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-don4ne_2/matplotlib/

I have already installed libfreetype6-dev but the pip command still reports missing this dependency.

# apt-get install libfreetype6-dev
Reading package lists... Done
Building dependency tree       
Reading state information... Done
libfreetype6-dev is already the newest version (2.6.1-0.1ubuntu2).
0 upgraded, 0 newly installed, 0 to remove and 4 not upgraded.

Is there an easy way to install all required dependencies for this python project?

Answer 1

If you are using Linux OS:

1. Remove matplotlib==1.3.1 from requirements.txt
2. Try to install matplotlib with sudo apt-get install python-matplotlib
3. Install all packages again from requirements.txt
   • For Python 2: run pip install -r requirements.txt
   • For Python 3: run pip3 install -r requirements.txt
4. pip freeze > requirements.txt

If you are using Windows OS:

1. python -m pip install -U pip setuptools
2. python -m pip install matplotlib

Answer 2

pip install -r requirements.txt for python 2.x

pip3 install -r requirements.txt for python 3.x (in case multiple versions are installed)

Answer 3

(Taken from my comment on another answer)

pip won't handle system-level dependencies. You'll have to apt-get install libfreetype6-dev before continuing. (It even says so right in your output. Try skimming over it for such errors next time, usually build outputs are very detailed.)

Answer 4

If you want to install all the dependencies inside the requirements file, like npm install on a Node.js project

in python you run the following command:

pip3 install -r  ./requirements.txt

you can use pip or pip3 both work

Answer 5

Python 3:

pip3 install -r requirements.txt

Python 2:

pip install -r requirements.txt

To get all the dependencies for the virtual environment or for the whole system:

pip freeze

To push all the dependencies to the requirements.txt (Linux):

pip freeze > requirements.txt

Answer 6

python -m pip install -r requirements.txt

Referece: How to install packages using pip according to the requirements.txt file from a local directory?