Re-defined variable from outer scope PYL-W0621
Anti-pattern
Major
2 years ago
—
2 years old
Redefining name 'friday' from outer scope (line 80)
66 self.translate(friday)
67 QtCore.QMetaObject.connectSlotsByName(friday)
68
69 def translate(self, friday):70 """Setting up icon and buttons"""
71 _translate = QtCore.QCoreApplication.translate
72 friday.setWindowTitle(_translate("friday", "FRIDAY"))Redefining name 'friday' from outer scope (line 80)
20 self.label = None
21 self.centralwidget = None
22
23 def setup(self, friday):24 """Setting up button sizes and text"""
25 friday.setObjectName("friday")
26 friday.resize(797, 581)
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()