super().__init__()

• using the % operator (old)

logger.debug('Got argument %s.' % arg)

• str.format (new: string formatters)

print("Sammy has {} balloons.".format(5))
print("Sammy has {} and {} balloons.".format(5, 7))
print("Sammy has {0} and {1} balloons.".format(5, 7))
print("Sammy has {1} and {0} balloons.".format(5, 7))

• interpolated strings

print("{firstname} {lastname}".format(firstname="Horst", lastname="Gutmann"))

• new f-strings in Python 3.6

name = 'Fred'
age = 42
print(f'He said his name is {name} and he is {age} years old.')

Logger is optimized to defer avaluation of arguments until it is needed, so for best performance use % formating. Instead of this:

logger.error('oops caused by %s' % exc)

do that:

logger.error('oops caused by %s', exc)

• exception-hierarchy
• Manually raising (throwing) an exception in Python

try:
    do_something()
except Exception:
    pass