Re-defined variable from outer scope PYL-W0621
Anti-pattern
Major
6 months ago
—
4 years old
Redefining name 'play' from outer scope (line 63)
61
62@UserBot.on_message(filters.command(["splay", "play"], ".") & (filters.me))
63async def play(bot: UserBot, message: Message):
64 play = await spotify.play()65 if play:
66 await message.edit("Spotify playback started")
67 else:Redefining name 'pause' from outer scope (line 50)
48
49@UserBot.on_message(filters.command(["spause", "pause"], ".") & (filters.me))
50async def pause(bot: UserBot, message: Message):
51 pause = await spotify.pause()52 if pause:
53 await message.edit("Spotify playback paused")
54 else:
Description
The local variable name hides the variable defined in the outer scope, making it inaccessible and might confuse.
Bad practice
filename = 'myfile.txt'
def read_file(filename): # This shadows the global `filename`
with open(filename) as file:
return file.readlines()
Preferred:
FILENAME = 'myfile.txt' # renamed global to UPPER_CASE as convention
def read_file(filename):
with open(filename) as file:
return file.readlines()
Bad practice
Another usual suspect of this is when you use the same parameter name inside a function as the global variable you are using. For example:
def run_app(app):
# This `app` shadows the global app...
app.run()
if __name__ == '__main__':
app = MyApp() # This is a global variable!
run_app(app)
Preferred:
To avoid this re-defining of a global, consider not defining app as a global, but inside a main() function instead:
def run_app(app):
# There is no longer a global `app` variable.
app.run()
def main():
app = MyApp()
run_app(app)
if __name__ == '__main__':
main()