ModuleNotFoundError: No module named 'MySQLdb'

Question

After finishing of one of my Flask projects, I uploaded it on github just like everybody else. after a 2-3 months period I downloaded the entire githube repository on another machine to run it. However, the app is not working because the packages are not found giving the following message

ModuleNotFoundError: No module named 'Flask'

So I ended up downloading all packages starting from Flask, SQLalchemy,..etc! but I got stuck with MySQLdb :

(MYAPPENV) C:\Users\hp\myapp>python run.py
Traceback (most recent call last):
  File "run.py", line 1, in <module>
    from app import app
  File "C:\Users\hp\myapp\app\__init__.py", line 4, in <module>
    from instance.config import engine
  File "C:\Users\hp\myapp\instance\config.py", line 52, in <module>
    engine = create_engine("mysql://root:root@localhost/MYAPPDB")
  File "C:\Users\hp\AppData\Local\Programs\Python\Python37-32\lib\site-packages\sqlalchemy\engine\__init__.py", line 425, in create_engine
return strategy.create(*args, **kwargs)
  File "C:\Users\hp\AppData\Local\Programs\Python\Python37-32\lib\site-packages\sqlalchemy\engine\strategies.py", line 81, in create
dbapi = dialect_cls.dbapi(**dbapi_args)
  File "C:\Users\hp\AppData\Local\Programs\Python\Python37-32\lib\site-packages\sqlalchemy\dialects\mysql\mysqldb.py", line 102, in dbapi
    return __import__('MySQLdb')
ModuleNotFoundError: No module named 'MySQLdb'

Could anybody please help with this issue? I am using python37 on windows machine. I even tried downloading packages such as mysqlclient,..etc but it didn't work out.

Answer 1

I have read that mysqldb is not supported by python3

And it looks like when you are trying to connect to your database you are using mysql db to connect to the database by default!

you need to change it by editing your DATABASE_URI configuration

But before you need to install the connector extension :

with this command :

pip install mysql-connector-python

And according to this documentation you can edit your DATABASE_URI and change the default connector like this :

DATABSE_URI='mysql+mysqlconnector://{user}:{password}@{server}/{database}'.format(user='your_user', password='password', server='localhost', database='dname')

I hope this will help...

Answer 2

You can install mysqlclient with pip

If using Python3 , try this:

pip3 install mysqlclient

or in Python2

pip install mysqlclient

Answer 3

要安装MySQLdb ，只要您的机器上安装了pip或pip3 ：

pip install mysqlclient

Answer 4

import pymysql
pymysql.install_as_MySQLdb()

Answer 5

I have the same problem like you. Here is my solution:

Reason: python3.X does not support MySQLdb,so you need to change to pymysql model

Solution: Change the content of import.

1):

replace all MySQLdb with pymysql

2):

def reconnect(self):
    """Closes the existing database connection and re-opens it."""
    self.close()
    self._db = pymysql.connect(**self._db_args)# MySQLdb.connect(**self._db_args)
    self._db.autocommit(True)

3)

if pymysql is not None:
    # Fix the access conversions to properly recognize unicode/binary
    FIELD_TYPE = pymysql.connections.FIELD_TYPE # MySQLdb.constants.FIELD_TYPE
    FLAG = pymysql.constants.FLAG# MySQLdb.constants.FLAG
    CONVERSIONS = copy.copy (pymysql.converters.conversions)# (MySQLdb.converters.conversions)

    field_types = [FIELD_TYPE.BLOB, FIELD_TYPE.STRING, FIELD_TYPE.VAR_STRING]
    if 'VARCHAR' in vars(FIELD_TYPE):
        field_types.append(FIELD_TYPE.VARCHAR)

    for field_type in field_types:
        # CONVERSIONS[field_type] = [(FLAG.BINARY, str)] + CONVERSIONS[field_type]
        CONVERSIONS[field_type] = [(FLAG.BINARY, str)].append(CONVERSIONS[field_type])

    # Alias some common MySQL exceptions
    IntegrityError = pymysql.IntegrityError# MySQLdb.IntegrityError
    OperationalError = pymysql.OperationalError# MySQLdb.OperationalError

4):

def __init__(self, host, database, user=None, password=None,
                 max_idle_time=7 * 3600, connect_timeout=10,# 设置连接超时时间，时间是秒
                 time_zone="+0:00", charset = "utf8", sql_mode="TRADITIONAL"):

5):

def query(self, query, *parameters, **kwparameters):
    """Returns a row list for the given query and parameters."""
    cursor = self._cursor()
    try:
        self._execute(cursor, query, parameters, kwparameters)
        column_names = [d[0] for d in cursor.description]
        return [Row(itertools.zip_longest(column_names, row)) for row in cursor]
    finally:
        cursor.close()

Answer 6

Hello internet people,

I reach this page because of the same problem.
But I'm using Ubuntu 18.04 and Python 3.6

Python snippet - app.py

from flask import Flask, render_template
from flask_mysqldb import MySQL

app = Flask(__name__)

app.config['MYSQL_HOST'] = 'YourHost' 
app.config['MYSQL_USER'] = 'YourUserName'
app.config['MYSQL_PASSWORD'] = 'UserPassword'
app.config['MYSQL_DB'] = 'TheDbName'
mysql = MySQL(app)

app.secret_key = 'YourUltimateSuperSecretKey'

@app.route('/')
@app.route('/index')
def index():
    cur = mysql.connection.cursor()
    cur.execute('SELECT * FROM users')
    data = cur.fetchall()
    cur.close()
    return render_template('index.html', test = data)

if __name__ == "__main__":
    app.run(debug=True)

HTML - index.html

<div>
    {% for x in test %}
        {{ x }}
    {% endfor %}
</div>

So this is what i did to solve the problem:
First I installed the missing package:

sudo apt install python3-mysqldb

After that I installed those libraries with pip on the environment:

pip install Flask-MySQLdb mysql-connector-python

and it worked :)

Answer 7

You should first install python3-dev, default-libmysqlclient-dev, build-essential then you can install mysqlclient.

For Red Hat

sudo yum install python3-devel mysql-devel
pip install mysqlclient

For Debian

sudo apt-get install python3-dev default-libmysqlclient-dev build-essential
pip install mysqlclient