No schema has been selected to create in ... error

Question

I am working on a Linux server that is hosted on Amazon's server and I have completely set up the server. The final thing I am trying to do is host one of my old projects that I created on the server which is in the Flask framework.

I am trying to run the Python file that sets up my database that is required to run my project.

I am using a virtual machine inside the server that will run my project and every time I run the command I get the following error:

(venv) grader@ip-10-20-6-95:/var/www/catalog/catalog$ python setup_database.py
Traceback (most recent call last):
  File "setup_database.py", line 63, in <module>
    Base.metadata.create_all(engine)
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/schema.py", line 2848, in create_all
    tables=tables)
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1479, in _run_visitor
    conn._run_visitor(visitorcallable, element, **kwargs)
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1122, in _run_visitor
    **kwargs).traverse_single(element)
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/sql/visitors.py", line 122, in traverse_single
    return meth(obj, **kw)
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/engine/ddl.py", line 70, in visit_metadata
    self.traverse_single(table, create_ok=True)
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/sql/visitors.py", line 122, in traverse_single
    return meth(obj, **kw)
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/engine/ddl.py", line 89, in visit_table
    self.connection.execute(schema.CreateTable(table))
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 662, in execute
    params)
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 720, in _execute_ddl
    compiled
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 874, in _execute_context
    context)
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1024, in _handle_dbapi_exception
    exc_info
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/util/compat.py", line 196, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb)
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 867, in _execute_context
    context)
  File "/var/www/catalog/venv/local/lib/python2.7/site-packages/sqlalchemy/engine/default.py", line 324, in do_execute
    cursor.execute(statement, parameters)
sqlalchemy.exc.ProgrammingError: (ProgrammingError) no schema has been selected to create in
 '\nCREATE TABLE users (\n\tid SERIAL NOT NULL, \n\tusername VARCHAR(100), \n\temail VARCHAR(225) NOT NULL, \n\tprofile_pic VARCHAR(225) NOT NULL, \n\tPRIMARY KEY (id)\n)\n\n' {}

I am not sure why I get this error.
The commands I ran to set up PostgreSQL (if that should matter):

$ sudo apt-get install libpq-dev python-dev
$ sudo apt-get install postgresql postgresql-contrib
$ sudo su - postgres
$ psql
# CREATE USER catalog WITH PASSWORD 'sillypassword';
# ALTER USER catalog CREATEDB;
# CREATE DATABASE catalog WITH OWNER catalog;
# \c catalog
# REVOKE ALL ON SCHEMA public FROM public;
# GRANT ALL ON SCHEMA public TO catalog;
# \q
$ exit

How could I fix this problem?

Answer 1

no schema has been selected to create in

You get this error when your search_path setting has no valid first entry (typically empty). Postgres does not know in which schema to create the table.

Fix your search_path setting, or schema-qualify object names (like: public.users). But fix your search_path in any case.
Details:

• How does the search_path influence identifier resolution and the "current schema"

Answer 2

This issue was answered already: https://dba.stackexchange.com/a/275116/114247

The fix is:

grant usage on schema public to public;
grant create on schema public to public;