mara_db.dbs.PostgreSQLDB does not work with port given as int

[akreuzer]

Running the following piece of code results in the exception below.

import mara_db.auto_migration
import mara_db.config
import mara_db.dbs

mara_db.config.databases = lambda: {
    "mara": mara_db.dbs.PostgreSQLDB(
        host="localhost", port=32768, user="postgres", database="example_etl_mara"
    )
}

print(mara_db.auto_migration.engine("mara"))

Exception:

<ipython-input-1-016eb66e9ef8> in <module>()
      9 }
     10
---> 11 print(mara_db.auto_migration.engine("mara"))

~/.python_envs/test/lib/python3.7/functools.py in wrapper(*args, **kw)
    818
    819     def wrapper(*args, **kw):
--> 820         return dispatch(args[0].__class__)(*args, **kw)
    821
    822     registry[object] = func

~/.python_envs/test/lib/python3.7/site-packages/mara_db/auto_migration.py in __(alias, **_)
    141 @engine.register(str)
    142 def __(alias: str, **_):
--> 143     return engine(mara_db.dbs.db(alias))
    144
    145

~/.python_envs/test/lib/python3.7/functools.py in wrapper(*args, **kw)
    818
    819     def wrapper(*args, **kw):
--> 820         return dispatch(args[0].__class__)(*args, **kw)
    821
    822     registry[object] = func

~/.python_envs/test/lib/python3.7/site-packages/mara_db/auto_migration.py in __(db)
    152 def __(db: mara_db.dbs.PostgreSQLDB):
    153     return sqlalchemy.create_engine(
--> 154         f'postgresql+psycopg2://{db.user}{":"+db.password if db.password else ""}@{db.host}{":"+db.port if db.port else "" }/{db.database}')
    155
    156

TypeError: can only concatenate str (not "int") to str

Passing the port as a string works.

I would have excepted that port is casted to str or that a more informative error is throw at the creation of the PostgreSQLDB object.