Multiple list comprehensions in one line in python
Question:
I have the following code in Python 3.9:
first_entries = [r[0] for r in result]
seconds_entries = [r[1] for r in result]
third_entries = [r[2] for r in result]
where result is a list of tuples of the following form:
result = [(x1,x2,x3),(y1,y2,y3),...]
Is there a way to write this into one line and iterate over result only once?
Answers:
tups = [(1,2,3), (4,5,6), (7,8,9), (10,11,12)]
first_entries, second_entries, third_entries = zip(*[(tup[0], tup[1], tup[2]) for tup in tups])
print(first_entries) # (1, 4, 7, 10)
Do you really need to separate those results into 3 lists though?
first_entries, seconds_entries, third_entries = zip(*result)
works as expected
I have the following code in Python 3.9:
first_entries = [r[0] for r in result]
seconds_entries = [r[1] for r in result]
third_entries = [r[2] for r in result]
where result is a list of tuples of the following form:
result = [(x1,x2,x3),(y1,y2,y3),...]
Is there a way to write this into one line and iterate over result only once?
tups = [(1,2,3), (4,5,6), (7,8,9), (10,11,12)]
first_entries, second_entries, third_entries = zip(*[(tup[0], tup[1], tup[2]) for tup in tups])
print(first_entries) # (1, 4, 7, 10)
Do you really need to separate those results into 3 lists though?
first_entries, seconds_entries, third_entries = zip(*result)
works as expected