Unnecessary comprehension PTC-W0016
Performance
Major
4 years ago
—
4 years old
Unnecessary comprehension -
join can take a generator172 return e
173
174 def __str__(self):
175 return " ENo: " + str(self.employee_id) + ", Designations :" + ",".join([str(designations) for designations in self.employee_designation.all()])
Description
The built-in function being used does not require comprehension and can work directly with a generator expression.
Using a generator expression within these functions is faster than using a comprehension:
allanyenumerateiteritertools.cycleitertools.accumulate
The inbuilt functions all() and any() in Python also support short-circuiting (evaluation stops as soon as the overall return value of the function is known), but this behavior is lost if you use a list comprehension. This affects performance.
Bad practice
# Takes a very long time to run
all_evens = all([n % 2 == 0 for n in range(100000000)])
if all_evens:
print('All numbers are even!')
Recommended
# No list comprehension, runs instantly as `1` is found to be not even
all_evens = all(n % 2 == 0 for n in range(100000000))
if all_evens:
print('The numbers are all even!')