Installing flask-mysqldb gives "mysql_config not found"

I'm trying to install flask-mysql on ubuntu 18.04 and I keep getting this error:

(base) ether@ether:~/Documents/loginsystem$ pip install flask-mysqldb
Collecting flask-mysqldb
  Using cached https://files.pythonhosted.org/packages/62/e3/955c845efe1aacf30c8e2607470544ede36aa1044f6382c809f13e014104/Flask-MySQLdb-0.2.0.tar.gz
Requirement already satisfied: Flask>=0.10 in /home/ether/anaconda3/lib/python3.7/site-packages (from flask-mysqldb) (1.0.2)
Collecting mysqlclient (from flask-mysqldb)
  Using cached https://files.pythonhosted.org/packages/d0/97/7326248ac8d5049968bf4ec708a5d3d4806e412a42e74160d7f266a3e03a/mysqlclient-1.4.6.tar.gz
    Complete output from command python setup.py egg_info:
    /bin/sh: 1: mysql_config: not found
    /bin/sh: 1: mariadb_config: not found
    /bin/sh: 1: mysql_config: not found
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-install-txlk8w2u/mysqlclient/setup.py", line 16, in <module>
        metadata, options = get_config()
      File "/tmp/pip-install-txlk8w2u/mysqlclient/setup_posix.py", line 61, in get_config
        libs = mysql_config("libs")
      File "/tmp/pip-install-txlk8w2u/mysqlclient/setup_posix.py", line 29, in mysql_config
        raise EnvironmentError("%s not found" % (_mysql_config_path,))
    OSError: mysql_config not found

    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-install-txlk8w2u/mysqlclient/

I tried to run sudo pip install and pip3 install flask-mysqldb but each time I received the same error as posted above.

What can I do to fix this?

Solution

The error message is pretty clear:

OSError: mysql_config not found

You need mysql_config. Install either libmariadbclient-dev or libmysqlclient-dev with apt.

Then try using pip again, but not with sudo.

Mixing system-level Python packages and pip-installed packages is a recipe for disaster. It looks like you already have a virtualenv for your project, so use that. Bonus points if you specify your dependencies in a requirements.txt file or Pipfile.