It's going to depend on what editor you are using, it's not a Python thing.
One thing that is a Python thing is triple quotes. A string that starts and ends with three quotes is a multi-line string, and is treated as a special kind of comment. So this:
for knight in camelot:
# knight.sing()
# knight.dance()
# knight.do_routines()
knight.footwork(impeccable = True)
print("It's only a model.")
Is equivalent to:
for knight in camelot:
"""knight.sing()
knight.dance()
knight.do_routines()"""
knight.footwork(impeccable = True)
print("It's only a model.")
So it's an easy way to comment out multiple lines.