Nested maps in Python 3

Question

I want to convert my list list = [" a , 1 ", " b , 2 "]

to a nested list [["a","1"],["b","2"]]

.

The following works:

f1_a = map(lambda x :[t.strip() for t in x.split(',',1)],list)

but this doesn't work with Python 3 (it does work with Python 2.7!):

f1_b = map(lambda x :map(lambda t:t.strip(),x.split(',',1)),list)

Why is this?

Is there a more concise way than f1_4

to achieve what I want?

+3

peer June 20. '15 at 9:41

1 answer

vaultah · Accepted Answer · 2015-06-20T09:44:19+0000

Python 3 map

returns an object map

that needs to be explicitly converted to a list:

f1_b = list(map(lambda x: list(map(lambda t: t.strip(), x.split(',', 1))), lst))

Although in most cases, you should prefer to list the errors map

:

f1_a = [[t.strip() for t in x.split(',', 1)] for x in lst]