is there a way to apply try/except logic to multiple class definitions without a try/except in every definition?
For example, instead of:
def test_table(tablename):
return Table(tablename, db.metadata, Column('id', Integer, primary_key=True))
class User(db.Model):
try:
__table__ = db.metadata.tables['user']
__bind_key__ = 'secondary'
# More attrs...
except KeyError:
__table__ = test_table('user')
class Policy(db.Model):
try:
__table__ = db.metadata.tables['policy']
__bind_key__ = 'secondary'
# More attrs...
except KeyError:
__table__ = test_table('policy')
I could apply logic with a decorator like:
@if_no_metadata_use_default('user')
class User(db.Model):
__table__ = db.metadata.tables['user']
__bind_key__ = 'secondary'
# More attrs...
@if_no_metadata_use_default('policy')
class Policy(db.Model):
__table__ = db.metadata.tables['policy']
__bind_key__ = 'secondary'
# More attrs...
This might not be a good practice in general since it really decreases your code readablity, but you can create an exception_wrapper
decorator like this:
def exception_wrapper(func):
def run(exception, on_exception, *args, **kwargs):
try:
return func(*args, **kwargs)
except exception:
on_exception()
return run
def on_exception():
pass
@exception_wrapper
def f(a, b):
if a < b:
raise NotImplementedError
return a + b
print(f(NotImplementedError, on_exception, 10, 2))
Again, I'm against using this kind of wrappers for exceptions since they will make your life harder in the long run, but it's up to you!