sqlalchemy.exc.ArgumentError: Can't load plugin: sqlalchemy.dialects:driver

Try those commands to install missing packages:

sudo apt-get install libpq-dev 
sudo pip install psycopg2 
sudo pip install redshift-sqlalchemy 
sudo pip install sqlparse

For those who haven’t noticed it, the “default-generated alembic.ini” zzzzeek refers to is in the root directory of the project.

The whole problem is one of setting the sqlalchemy.url config parameter in the alembic.ini file. Also, it can be set programmatically as explained in https://stackoverflow.com/a/15668175/973380.

Notice that the scheme doesn’t actually specify the driver but the dialect: the scheme is of form dialect:// or dialect+driver://.

For example the correct urls to connect to a PostgreSQL database would start with for example postgres:// (which defaults to using psycopg2), or choosing a driver explicitly (postgres+psycopg2://, or with another driver).

If you happen to specify only psycopg2 you will get the error

sqlalchemy.exc.NoSuchModuleError: Can't load plugin: sqlalchemy.dialects:psycopg2

To get the Teradata Queries to run on the .exe produced by Pyinstaller. I changed my engine from SQLAlchemy to Teradata

From :

import sqlalchemy as sa
user, pasw, hostname = UserName,Password, 'myurl.com'
# connect
td_engine = sa.create_engine('teradata://{}:{}@{}:22/'.format(user,pasw,hostname),echo=True)
df = pd.read_sql_query(query1,connect)

To:

import teradata
user, pasw, hostname = UserName,Password, 'myurl.com'
td = teradata.UdaExec (appName="test", version="1.0", logConsole=True)
td_engine = td.connect(method="odbc",system=hostname, username=user,password=pasw,driver="Teradata") 

I did,

pip install ibm_db_sa

it fixed problem

uninstall anaconda if you have it. it is installing your mysql connector in the anaconda path and your code is probably looking in the python path.

I resolved this by simply opening the alembic.ini in notepad++ and then amending the variable sqlachemy.url (on about line 38) to the url in my project file. The error is most likely caused because it has driver at the beginning.

i.e. renaming this line to

sqlalchemy.url = sqlite:///name_of_my_database.db

To programmatically override the default value in alembic.ini, you can add a line or two of code in alembic/env.py:

+ import app

[...snip...]

  # this is the Alembic Config object, which provides
  # access to the values within the .ini file in use.
  config = context.config

+ config.set_section_option(
    config.config_ini_section, "sqlalchemy.url", app.settings.SQLALCHEMY_DATABASE_URL
)

where import app and app.settings.SQLALCHEMY_DATABASE_URL are replaced by your own application-specific code to retrieve the URL.

If you were following the correct syntax for creating an engine, depending on your database of choice, create_engine(f"<dialect_name>+<driver_name>://{self.user}:{self.password}@{self.host}:{self.port}/{self.database}) and none of the other suggestions here fix your problem, you can try the solution outlined in the next paragraph.

The issue, NoSuchModuleError: Can't load plugin: sqlalchemy.dialects:<dialect_name>.<driver_name>, can be caused by running an SQLAlchemy version that does support the driver you need. For example, SQLAlchemy 1.4.26 supports these PostgreSQL drivers. So, the solution:

1. Check the documentation for supported drivers, for the dialect you need.
2. Then uninstall SQLAlchemy or the problematic driver pip uninstall SQLAlchemy
3. Force pip to install specific version of SQLAlchemy or an alternative driver, pip install SQLAlchemy==1.0.14

connection_url=""  
#your database connection string here pulled from either environment variable , vaults or can be set directly

def run_migrations_offline():
    """Run migrations in 'offline' mode.

    This configures the context with just a URL
    and not an Engine, though an Engine is acceptable
    here as well.  By skipping the Engine creation
    we don't even need a DBAPI to be available.

    Calls to context.execute() here emit the given string to the
    script output.

    """
    url = connection_url 
    context.configure(
        url=url,
        target_metadata=target_metadata,
        literal_binds=True,
        dialect_opts={"paramstyle": "named"},
    )

    with context.begin_transaction():
        context.run_migrations()


def run_migrations_online():
    """Run migrations in 'online' mode.

    In this scenario we need to create an Engine
    and associate a connection with the context.

    """
    configdict=config.get_section(config.config_ini_section)
    configdict.update({"sqlalchemy.url":connection_url})
    connectable = engine_from_config(
        configdict,
        prefix="sqlalchemy.",
        poolclass=pool.NullPool,
    )

    with connectable.connect() as connection:
        context.configure(
            connection=connection, target_metadata=target_metadata
        )

        with context.begin_transaction():
            context.run_migrations()

if you want to read the connection url from your python file itself without refering to default

alembic.ini

config file.