MySQL connection fails with special characters in password - OperationalError 2003

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1

I’m trying to connect to MySQL database using SQLAlchemy but getting connection errors when my password contains special characters like @ symbol.

from sqlalchemy import create_engine
import pymysql

user_name = "admin_user"
user_password = "pass@456"
database_name = "myapp_db"
server_host = "localhost"

db_engine = create_engine(
    f'mysql+pymysql://{user_name}:{user_password}@{server_host}/{database_name}',
    pool_pre_ping=True,
    pool_recycle=300
)

This throws an error:

pymysql.err.OperationalError: (2003, "Can't connect to MySQL server on '456@localhost' ([Errno -2] Name or service not known)")

The issue happens because the @ character in password gets parsed incorrectly. Here’s how I fixed it using URL encoding:

from sqlalchemy import create_engine
import pymysql
import urllib.parse

user_name = "admin_user"
user_password = "pass@456"
encoded_password = urllib.parse.quote_plus(user_password)
database_name = "myapp_db"
server_host = "localhost"

db_engine = create_engine(
    f'mysql+pymysql://{user_name}:{encoded_password}@{server_host}/{database_name}',
    pool_pre_ping=True,
    pool_recycle=300
)

The urllib.parse.quote_plus() function properly encodes special characters in the password string, preventing connection string parsing issues.

2

totally get it! i had the same trouble too. using URL.create() from SQLAlchemy is a gr8 idea - it manages encoding automatically and looks neater. def less hassle than dealing with this manually :slight_smile: