ImportError: No module named 'psycopg2._psycopg'

When I try to import psycopg2 it show below log for me:

Traceback (most recent call last):
  File "D:/Desktop/learn/python/webcatch/appserver/testpgsql.py", line 2, in <module>
    import psycopg2
  File "D:/Desktop/learn/python/webcatch/appserver/webcatch/lib/site-packages/psycopg2-2.6.1-py3.5-win32.egg/psycopg2/__init__.py", line 50, in <module>
    from psycopg2._psycopg import BINARY, NUMBER, STRING, DATETIME, ROWID
ImportError: No module named 'psycopg2._psycopg'

How can I solve it? My platform is win10 (64) and version is python 3.5

Eureka! I pulled my hair out for 2 days trying to get this to work. Enlightenment came from this SO Question. Simply stated, you probably installed psycopg2 x64 version like I did, not realizing your python version was 32-bit. Unistall your current psycopg2, then:

Download: psycopg2-2.6.1.win32-py3.4-pg9.4.4-release.exe from HERE, then run the following in a Terminal:

C:\path\to\project> easy_install /path/to/psycopg2-2.6.1.win32-py3.4-pg9.4.4-release.exe
C:\path\to\project> python manage.py makemigrations
C:\path\to\project> python manage.py migrate

You may also need to (re)create super user with:

C:\path\to\project> python manage.py createsuperuser

I had the same problem, solved it in this way:

Reinstall the package psycopg2 using pip (by default installed with python 3)

On Linux:

pip uninstall psycopg2

Confirm with (y) and then:

pip install psycopg2

On Windows I add the prefix ('python -m') to the commands above. I think the problem occurs when you change the version of Python. (Even between minor versions such as Python 3.5 and 3.6).

I am using psycopg in an AWS Glue Job, where is harder to follow the instructions listed in the other answers.

What I did is installing psycopg2-binary into a directory and zip up the contents of that directory:

mkdir psycopg2-binary
cd psycopg2-binary
pip install psycopg2-binary -t  .
# in case using python3:
# python3 -m pip install --system psycopg2-binary -t  .
zip -r9 psycopg2.zip *

I then copied psycopg2.zip to an S3 bucket and add it as an extra Python library under "Python library path" in the Glue Spark job.

I then launched the job with the following script to verify if psycopg2 is present (the zip file will be downloaded by Glue into the directory in which the Job script is located)

from awsglue.transforms import *
from awsglue.utils import getResolvedOptions
from pyspark.context import SparkContext
from awsglue.context import GlueContext
from awsglue.job import Job
import sys
import os
import zipfile

## @params: [JOB_NAME]
args = getResolvedOptions(sys.argv, ['JOB_NAME'])

sc = SparkContext()
glueContext = GlueContext(sc)
spark = glueContext.spark_session
job = Job(glueContext)
job.init(args['JOB_NAME'], args)

zip_ref = zipfile.ZipFile('./psycopg2.zip', 'r')
print os.listdir('.')
zip_ref.extractall('/tmp/packages')
zip_ref.close()
sys.path.insert(0, '/tmp/packages')

import psycopg2
print(psycopg2.__version__)

job.commit()

Download the compiled version of psycopg2 from this link https://github.com/jkehler/awslambda-psycopg2. As psycopg2 is C library for python, which need to be compiled on linux to make it work. The compile instruction also given on that link. Thanks to the https://github.com/jkehler.

This also happens to me in new Ubuntu 18.04. It is caused by missing one file _psycopg.py in the /usr/local/lib/python3.7/site-packages/psycopg2.

It is fixed by:

1. remove the old psycopg2 from your machine pip3 uninstall psycopg2.
2. download new pyscopg2 manually from the official page http://initd.org/psycopg/tarballs/PSYCOPG-2-7/psycopg2-2.7.7.tar.gz
3. tar xvf psycopg2-2.7.7.tar.gz
4. python setup.py build
5. sudo python setup.py install