Tag: Python

ModuleNotFoundError: No module named ‘MySQLdb’
When running migration for a Django application with “python manage.py migrate”, I got the following error message
```
ModuleNotFoundError: No module named 'MySQLdb'
```
To fix install
```
pip install mysqlclient
```
This will require MySQL development package. On the Ubuntu server running MariaDB, I installed packaged libmariadb-dev
```
sudo apt install libmariadb-dev
```
Back to Errors
December 9, 2022
error: invalid command ‘bdist_wheel’
When installing a python module on Ubuntu, I got the following error message
```
error: invalid command 'bdist_wheel'
```
The error is fixed by installing
```
apt install -y python3-dev libpq-dev python3-wheel gcc
pip3 install wheel
```
Back to Errors
December 9, 2022

How to install Python 3.10 on CentOS 7

First, install the dependency

yum install -y wget zlib-devel
yum groupinstall -y "Development tools"

Install OpenSSL as the openssl-devel package provided by CentOS is old version. Install OpenSSL from source with

cd /usr/local/src
wget https://www.openssl.org/source/openssl-1.1.1g.tar.gz
tar xvf openssl-1.1.1g.tar.gz
cd openssl-1.1.1g
./config --prefix=/usr/serverok/openssl --openssldir=/usr/serverok/openssl no-ssl2
make
make install

Run following commands

export PATH=/usr/serverok/openssl/bin:$PATH
export LD_LIBRARY_PATH=/usr/serverok/openssl/lib
export LC_ALL="en_US.UTF-8"
export LDFLAGS="-L/usr/serverok/openssl/lib -Wl,-rpath,/usr/serverok/openssl/lib"

Download the latest version of Python from

https://www.python.org/downloads/

To install, run

cd /usr/local/src
wget https://www.python.org/ftp/python/3.10.6/Python-3.10.6.tar.xz
tar xvf Python-3.10.6.tar.xz
cd /usr/local/src/Python-3.10.6
make clean && make distclean
./configure --enable-optimizations  --with-openssl=/usr/serverok/openssl/
make altinstall

Python 10 will be installed in folder

/usr/local/bin/python3.10

To install pip modules, you can use

python3.10 -m pip install -r requirements.txt

Back to Python

August 30, 2022

ModuleNotFoundError: No module named ‘PIL’

When running a python application, I got the error message ModuleNotFoundError: No module named ‘PIL’

(venv) boby@sok-01:~/work/powder (master)$ python main.py 
Traceback (most recent call last):
  File "main.py", line 6, in 
    from extras import *
  File "/home/boby/work/powder/extras.py", line 2, in 
    from PIL import Image, ImageDraw, ImageFont
ModuleNotFoundError: No module named 'PIL'
(venv) boby@sok-01:~/work/powder (master)$

To fix the error install Pillow with

pip install Pillow

June 26, 2022

OSError: mysql_config not found
When installing the python mysqlclient module with pip, I got the error “OSError: mysql_config not found”.

(venv) root@sok:~# pip install mysqlclient
Collecting mysqlclient
Downloading mysqlclient-2.1.0.tar.gz (87 kB)
|████████████████████████████████| 87 kB 1.2 MB/s
ERROR: Command errored out with exit status 1:
command: /root/venv/bin/python3 -c ‘import sys, setuptools, tokenize; sys.argv[0] = ‘”‘”‘/tmp/pip-install-r5qp0a97/mysqlclient/setup.py’”‘”‘; __file__=’”‘”‘/tmp/pip-install-r5qp0a97/mysqlclient/setup.py’”‘”‘;f=getattr(tokenize, ‘”‘”‘open’”‘”‘, open)(__file__);code=f.read().replace(‘”‘”‘\r\n’”‘”‘, ‘”‘”‘\n’”‘”‘);f.close();exec(compile(code, __file__, ‘”‘”‘exec’”‘”‘))’ egg_info –egg-base /tmp/pip-install-r5qp0a97/mysqlclient/pip-egg-info
cwd: /tmp/pip-install-r5qp0a97/mysqlclient/
Complete output (15 lines):
/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 ““, line 1, in
File “/tmp/pip-install-r5qp0a97/mysqlclient/setup.py”, line 15, in
metadata, options = get_config()
File “/tmp/pip-install-r5qp0a97/mysqlclient/setup_posix.py”, line 70, in get_config
libs = mysql_config(“libs”)
File “/tmp/pip-install-r5qp0a97/mysqlclient/setup_posix.py”, line 31, in mysql_config
raise OSError(“{} not found”.format(_mysql_config_path))
OSError: mysql_config not found
mysql_config –version
mariadb_config –version
mysql_config –libs
—————————————-
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.
(venv) root@sok:~#

The error is fixed by installing MySQL development library.

On Ubuntu server with MariaDB, i installed
```
apt install libmariadb-dev
```
For MySQL, you can use
```
apt-get install libmysqlclient-dev
```
February 21, 2022
Uvicorn
Uvicorn is a lightning-fast ASGI server used to serve Python ASGI frameworks like FastAPI, Django Channels, Quart, BlackSheep, etc…

https://www.uvicorn.org

To install Uvicorn, run
```
pip install uvicorn
```
To run, you can use
```
uvicorn main:app --host 0.0.0.0 --port 8000 --reload
```
See Python
September 11, 2021
Flask Python framework
Flask is a Python framework. You can find more info at the official website.

https://flask.palletsprojects.com/

How to start a Flask application?

To start flask application, run
```
python app.py
```
How to run flask application on port 80

To run flask application on port 80, use command
```
flask run --host 0.0.0.0 --port 80
```
Or edit app.py, use the following code
```
if __name__ == '__main__':
    app.run(host='0.0.0.0', port=80)
```
Or you can use the following environment variables
```
FLASK_RUN_HOST=0.0.0.0
FLASK_RUN_PORT=80
```
Port 80 can only be used by the root user, so you need to run the above command as root. Only do this for testing as it is insecure to run an application as the root user.

Default flask app name

When you run
```
flash run
```
It looks for app.py file. If you need to change the file name, you can use the environment variable
```
FLASK_APP=application.py
```
See python
August 20, 2021

Install Python 3.8 on CentOS 6 from source

To install Python 3.8 on CentOS, you need to install OpenSSL as the one installed by CentOS from yum is very old.

cd /usr/local/src
wget https://www.openssl.org/source/openssl-1.1.1g.tar.gz
tar xvf openssl-1.1.1g.tar.gz
cd openssl-1.1.1g
./config --prefix=/usr/serverok/openssl --openssldir=/usr/serverok/openssl no-ssl2
make
make install

Now edit file

vi ~/.bash_profile

at end of the file, add

export PATH=/usr/serverok/openssl/bin:$PATH
export LD_LIBRARY_PATH=/usr/serverok/openssl/lib
export LC_ALL="en_US.UTF-8"
export LDFLAGS="-L/usr/serverok/openssl/lib -Wl,-rpath,/usr/serverok/openssl/lib"

Make the settings active with command

source ~/.bash_profile

Now we can install Python 3.8 with

cd /usr/local/src
wget https://www.python.org/ftp/python/3.8.4/Python-3.8.4.tar.xz
tar xvf Python-3.8.4.tar.xz
cd /usr/local/src/Python-3.8.4
make clean && make distclean
./configure --enable-optimizations  --with-openssl=/usr/serverok/openssl/
make altinstall

Now python 3.8 will be available in your system under /usr/local/bin

root@server12:~# python3.8 --version
Python 3.8.4
root@server12:~# which python3.8
/usr/local/bin/python3.8
root@server12:~#

July 18, 2020

Python mechanize HTTP Error 403 request disallowed by robots.txt

When running following python script i get error “HTTP Error 403 request disallowed by robots.txt”

from mechanize import Browser

a = ['https://google.com', 'https://serverok.in', 'https://msn.com']

br = Browser() 

for x in range(len(a)):     
    br.open(a[x]) 
    print("Website title: ")
    print(br.title())
    print("\n")

To fix this, find

br = Browser()

Add below

br.set_handle_robots(False)
br.addheaders = [('User-agent', 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.77 Safari/537.36')]

set_handle_robots is used to disable robots.txt checking. Second line will set a User-agent, so remote won’t won’t block you as a robot.

See Python

June 1, 2020

error: Python.h: No such file or directory
When install dlib python module, i get error
```
ERROR: Failed building wheel for dlib fatal 
error: Python.h: No such file or directory
```
This is because missing python3-dev package. To fix, install
```
apt install python3-dev
```
If you are using python virtualenv, you will need to recreate the virtualenv after installing dev package.
```
virtualenv -p /usr/bin/python3 venv
```
February 16, 2020

ERROR: Failed building wheel for mysqlclient

When install mysqlclient python module, i get error

(venv) boby@sok-01:~/Downloads/django-deploy$ pip install mysqlclient==1.4.2.post1
Collecting mysqlclient==1.4.2.post1
  Using cached https://files.pythonhosted.org/packages/f4/f1/3bb6f64ca7a429729413e6556b7ba5976df06019a5245a43d36032f1061e/mysqlclient-1.4.2.post1.tar.gz
Building wheels for collected packages: mysqlclient
  Building wheel for mysqlclient (setup.py) ... error
  ERROR: Complete output from command /home/boby/venv/bin/python3 -u -c 'import setuptools, tokenize;__file__='"'"'/tmp/pip-install-bbfa8tuo/mysqlclient/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' bdist_wheel -d /tmp/pip-wheel-bqlba1jk --python-tag cp36:
  ERROR: running bdist_wheel
  running build
  running build_py
  creating build
  creating build/lib.linux-x86_64-3.6
  creating build/lib.linux-x86_64-3.6/MySQLdb
  copying MySQLdb/__init__.py -> build/lib.linux-x86_64-3.6/MySQLdb
  copying MySQLdb/_exceptions.py -> build/lib.linux-x86_64-3.6/MySQLdb
  copying MySQLdb/compat.py -> build/lib.linux-x86_64-3.6/MySQLdb
  copying MySQLdb/connections.py -> build/lib.linux-x86_64-3.6/MySQLdb
  copying MySQLdb/converters.py -> build/lib.linux-x86_64-3.6/MySQLdb
  copying MySQLdb/cursors.py -> build/lib.linux-x86_64-3.6/MySQLdb
  copying MySQLdb/release.py -> build/lib.linux-x86_64-3.6/MySQLdb
  copying MySQLdb/times.py -> build/lib.linux-x86_64-3.6/MySQLdb
  creating build/lib.linux-x86_64-3.6/MySQLdb/constants
  copying MySQLdb/constants/__init__.py -> build/lib.linux-x86_64-3.6/MySQLdb/constants
  copying MySQLdb/constants/CLIENT.py -> build/lib.linux-x86_64-3.6/MySQLdb/constants
  copying MySQLdb/constants/CR.py -> build/lib.linux-x86_64-3.6/MySQLdb/constants
  copying MySQLdb/constants/ER.py -> build/lib.linux-x86_64-3.6/MySQLdb/constants
  copying MySQLdb/constants/FIELD_TYPE.py -> build/lib.linux-x86_64-3.6/MySQLdb/constants
  copying MySQLdb/constants/FLAG.py -> build/lib.linux-x86_64-3.6/MySQLdb/constants
  running build_ext
  building 'MySQLdb._mysql' extension
  creating build/temp.linux-x86_64-3.6
  creating build/temp.linux-x86_64-3.6/MySQLdb
  x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -g -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC -Dversion_info=(1,4,2,'post',1) -D__version__=1.4.2.post1 -I/usr/include/mysql -I/usr/include/python3.6m -I/home/boby/venv/include/python3.6m -c MySQLdb/_mysql.c -o build/temp.linux-x86_64-3.6/MySQLdb/_mysql.o
  MySQLdb/_mysql.c:37:10: fatal error: Python.h: No such file or directory
   #include "Python.h"
            ^~~~~~~~~~
  compilation terminated.
  error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
  ----------------------------------------
  ERROR: Failed building wheel for mysqlclient
  Running setup.py clean for mysqlclient
Failed to build mysqlclient
Installing collected packages: mysqlclient
  Running setup.py install for mysqlclient ... error
    ERROR: Complete output from command /home/boby/venv/bin/python3 -u -c 'import setuptools, tokenize;__file__='"'"'/tmp/pip-install-bbfa8tuo/mysqlclient/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /tmp/pip-record-t_mzj872/install-record.txt --single-version-externally-managed --compile --install-headers /home/boby/venv/include/site/python3.6/mysqlclient:
    ERROR: running install
    running build
    running build_py
    creating build
    creating build/lib.linux-x86_64-3.6
    creating build/lib.linux-x86_64-3.6/MySQLdb
    copying MySQLdb/__init__.py -> build/lib.linux-x86_64-3.6/MySQLdb
    copying MySQLdb/_exceptions.py -> build/lib.linux-x86_64-3.6/MySQLdb
    copying MySQLdb/compat.py -> build/lib.linux-x86_64-3.6/MySQLdb
    copying MySQLdb/connections.py -> build/lib.linux-x86_64-3.6/MySQLdb
    copying MySQLdb/converters.py -> build/lib.linux-x86_64-3.6/MySQLdb
    copying MySQLdb/cursors.py -> build/lib.linux-x86_64-3.6/MySQLdb
    copying MySQLdb/release.py -> build/lib.linux-x86_64-3.6/MySQLdb
    copying MySQLdb/times.py -> build/lib.linux-x86_64-3.6/MySQLdb
    creating build/lib.linux-x86_64-3.6/MySQLdb/constants
    copying MySQLdb/constants/__init__.py -> build/lib.linux-x86_64-3.6/MySQLdb/constants
    copying MySQLdb/constants/CLIENT.py -> build/lib.linux-x86_64-3.6/MySQLdb/constants
    copying MySQLdb/constants/CR.py -> build/lib.linux-x86_64-3.6/MySQLdb/constants
    copying MySQLdb/constants/ER.py -> build/lib.linux-x86_64-3.6/MySQLdb/constants
    copying MySQLdb/constants/FIELD_TYPE.py -> build/lib.linux-x86_64-3.6/MySQLdb/constants
    copying MySQLdb/constants/FLAG.py -> build/lib.linux-x86_64-3.6/MySQLdb/constants
    running build_ext
    building 'MySQLdb._mysql' extension
    creating build/temp.linux-x86_64-3.6
    creating build/temp.linux-x86_64-3.6/MySQLdb
    x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -g -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC -Dversion_info=(1,4,2,'post',1) -D__version__=1.4.2.post1 -I/usr/include/mysql -I/usr/include/python3.6m -I/home/boby/venv/include/python3.6m -c MySQLdb/_mysql.c -o build/temp.linux-x86_64-3.6/MySQLdb/_mysql.o
    MySQLdb/_mysql.c:37:10: fatal error: Python.h: No such file or directory
     #include "Python.h"
              ^~~~~~~~~~
    compilation terminated.
    error: command 'x86_64-linux-gnu-gcc' failed with exit status 1
    ----------------------------------------
ERROR: Command "/home/boby/venv/bin/python3 -u -c 'import setuptools, tokenize;__file__='"'"'/tmp/pip-install-bbfa8tuo/mysqlclient/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record /tmp/pip-record-t_mzj872/install-record.txt --single-version-externally-managed --compile --install-headers /home/boby/venv/include/site/python3.6/mysqlclient" failed with error code 1 in /tmp/pip-install-bbfa8tuo/mysqlclient/
WARNING: You are using pip version 19.1.1, however version 19.2.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
(venv) boby@sok-01:~/Downloads/django-deploy$

Fixed by installing

sudo apt-get install python3-dev

August 1, 2019

pip install mysqlclient mysql_config: not found

On Ubuntu 18.04, when i install mysqlclient python module, i get error

(venv) boby@sok-01:~/Downloads/django-deploy$ pip install mysqlclient==1.4.2.post1
Collecting mysqlclient==1.4.2.post1
  Using cached https://files.pythonhosted.org/packages/f4/f1/3bb6f64ca7a429729413e6556b7ba5976df06019a5245a43d36032f1061e/mysqlclient-1.4.2.post1.tar.gz
    ERROR: Complete output from command python setup.py egg_info:
    ERROR: /bin/sh: 1: mysql_config: not found
    Traceback (most recent call last):
      File "", line 1, in 
      File "/tmp/pip-install-we5rsid9/mysqlclient/setup.py", line 16, in 
        metadata, options = get_config()
      File "/tmp/pip-install-we5rsid9/mysqlclient/setup_posix.py", line 51, in get_config
        libs = mysql_config("libs")
      File "/tmp/pip-install-we5rsid9/mysqlclient/setup_posix.py", line 29, in mysql_config
        raise EnvironmentError("%s not found" % (_mysql_config_path,))
    OSError: mysql_config not found
    ----------------------------------------
ERROR: Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-install-we5rsid9/mysqlclient/
WARNING: You are using pip version 19.1.1, however version 19.2.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
(venv) boby@sok-01:~/Downloads/django-deploy$

this is fixed by installing libmysqlclient-dev

apt install libmysqlclient-dev

ERROR: Failed building wheel for mysqlclient

See Python

August 1, 2019

Tag: Python

How to start a Flask application?

How to run flask application on port 80

Default flask app name