Django/Python Beginner: Error when executing python manage.py syncdb - psycopg2 not found

Question

Hello,

I have Pythong2.6, psycopg2 and pgAdmin3 installed using Macports. My settings.py is:

DATABASE_ENGINE = 'postgresql_psycopg2'           # 'postgresql_psycopg2', 'postgresql', 'mysql', 'sqlite3' or 'oracle'.
DATABASE_NAME = 'mysite'             # Or path to database file if using sqlite3.
DATABASE_USER = 'postgres'             # Not used with sqlite3.
DATABASE_PASSWORD = ''         # Not used with sqlite3.
DATABASE_HOST = ''             # Set to empty string for localhost. Not used with sqlite3.
DATABASE_PORT = ''             # Set to empty string for default. Not used with sqlite3.

The error I get when I run python manage.py syncdb is:

Traceback (most recent call last):
  File "manage.py", line 11, in <module>
    execute_manager(settings)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/core/management/__init__.py", line 362, in execute_manager
    utility.execute()
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/core/management/__init__.py", line 303, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/core/management/base.py", line 195, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/core/management/base.py", line 221, in execute
    self.validate()
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/core/management/base.py", line 249, in validate
    num_errors = get_validation_errors(s, app)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/core/management/validation.py", line 22, in get_validation_errors
    from django.db import models, connection
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/db/__init__.py", line 41, in <module>
    backend = load_backend(settings.DATABASE_ENGINE)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/db/__init__.py", line 17, in load_backend
    return import_module('.base', 'django.db.backends.%s' % backend_name)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/utils/importlib.py", line 35, in import_module
    __import__(name)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/db/backends/postgresql_psycopg2/base.py", line 22, in <module>
    raise ImproperlyConfigured("Error loading psycopg2 module: %s" % e)
django.core.exceptions.ImproperlyConfigured: Error loading psycopg2 module: No module named psycopg2

Please note, I am a complete beginner in this stuff. I am originally a PHP-guy and trying out Python for a small personal project. Do I need to "turn on" Postgres?

Also, when I sudo python manage.py runserver 8080 I get this error:

Validating models...
Unhandled exception in thread started by <function inner_run at 0x1242670>
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/core/management/commands/runserver.py", line 48, in inner_run
    self.validate(display_num_errors=True)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/core/management/base.py", line 249, in validate
    num_errors = get_validation_errors(s, app)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/core/management/validation.py", line 22, in get_validation_errors
    from django.db import models, connection
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/db/__init__.py", line 41, in <module>
    backend = load_backend(settings.DATABASE_ENGINE)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/db/__init__.py", line 17, in load_backend
    return import_module('.base', 'django.db.backends.%s' % backend_name)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/utils/importlib.py", line 35, in import_module
    __import__(name)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/django/db/backends/postgresql_psycopg2/base.py", line 22, in <module>
    raise ImproperlyConfigured("Error loading psycopg2 module: %s" % e)
django.core.exceptions.ImproperlyConfigured: Error loading psycopg2 module: No module named psycopg2

Please guide me. Any reply will be appreciated.

Thanks,

Wenbert!

Answer 1

Although you installed it, Python can apparently not find the module psycopg2. This is usually due to the module not being in Python's path. See if you can find a folder named psycopg2 in /Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages. If it's not there, did MacPorts tell you where it put psycopg2? If you can locate it, just move it to the site-packages directory and you should be fine.

Answer 2

There seems to be a problem with your psycopg2 installation – Python does not find it. This is a Python installation problem, not a Django issue.

You can try to load it manually using the Python interpreter and see if it works:

$ python
>>> import psycopg2

If you get an ImportError exception, your installation is erroneous. To get a list of all directories Python looks for modules, use sys.path:

$ python
>>> import sys
>>> print sys.path

You can also add custom directories to Python's module search path by modifying the sys.path variable. Do this somewhere before the respective import statement(s):

import sys
sys.path.append("my-path")

# ...
import psycopg2