CODEWITHSUNDEEP
pythonpython-3.xpsycopg2postgresql-9.1
arilwan
arilwan

Reputation: 3993

PostgreSQL- ModuleNotFoundError: No module named 'psycopg2'

I can confirm psycopg2 is install (using conda install -c anaconda psycopg2) but the it seems psycopg2 cannot be imported to my python script or the interpreter is unable to locate it. I also tried installing using pip3, requirements are satisfied, meaning psycopg2 is already istalled, but cannot understand why I script isn't able to import it. Using Mac (OS v10.14.4) 

$ python create_tables.py
Traceback (most recent call last):
  File "create_tables.py", line 1, in <module>
    import psycopg2
ModuleNotFoundError: No module named 'psycopg2'

$ pip3 install psycopg2
Requirement already satisfied: psycopg2 in /usr/local/lib/python3.7/site-packages (2.8.2)
$ pip3 install psycopg2-binary
Requirement already satisfied: psycopg2-binary in /usr/local/lib/python3.7/site-packages (2.8.2)
python -V
Python 3.7.0

Any idea why this happen?

EDIT: create_table.py

import psycopg2
from config import config


def create_tables():
    """ create tables in the PostgreSQL database"""
    commands = (
        """
        CREATE TABLE vendors (
            vendor_id SERIAL PRIMARY KEY,
            vendor_name VARCHAR(255) NOT NULL
        )
        """,
        """ CREATE TABLE parts (
                part_id SERIAL PRIMARY KEY,
                part_name VARCHAR(255) NOT NULL
                )
        """,
        """
        CREATE TABLE part_drawings (
                part_id INTEGER PRIMARY KEY,
                file_extension VARCHAR(5) NOT NULL,
                drawing_data BYTEA NOT NULL,
                FOREIGN KEY (part_id)
                REFERENCES parts (part_id)
                ON UPDATE CASCADE ON DELETE CASCADE
        )
        """,
        """
        CREATE TABLE vendor_parts (
                vendor_id INTEGER NOT NULL,
                part_id INTEGER NOT NULL,
                PRIMARY KEY (vendor_id , part_id),
                FOREIGN KEY (vendor_id)
                    REFERENCES vendors (vendor_id)
                    ON UPDATE CASCADE ON DELETE CASCADE,
                FOREIGN KEY (part_id)
                    REFERENCES parts (part_id)
                    ON UPDATE CASCADE ON DELETE CASCADE
        )
        """)
    conn = None
    try:
        # read the connection parameters
        params = config()
        # connect to the PostgreSQL server
        conn = psycopg2.connect(**params)
        cur = conn.cursor()
        # create table one by one
        for command in commands:
            cur.execute(command)
        # close communication with the PostgreSQL database server
        cur.close()
        # commit the changes
        conn.commit()
    except (Exception, psycopg2.DatabaseError) as error:
        print(error)
    finally:
        if conn is not None:
            conn.close()


if __name__ == '__main__':
    create_tables()

Upvotes: 22

Views: 37099

Answers (3)

me72921
me72921

Reputation: 173

Using Python3 the command is:

python3 -m pip install psycopg2-binary

Upvotes: 3

arilwan
arilwan

Reputation: 3993

Yes, found a solution,

python -m pip install psycopg2-binary

does the trick!

Upvotes: 44

Devesh Kumar Singh
Devesh Kumar Singh

Reputation: 20500

I assume python points to python2, but you installed psycopg2 for python3 since you are using pip3. Install it via pip install pyscopg2 psycopg2-binary where pip should point to python2

Upvotes: 0

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