Python - Ways to iterate tuple list of lists

List is an important container and used almost in every code of day-day programming as well as web-development, more it is used, more is the requirement to master it and hence knowledge of its operations is necessary.

Example

# using itertools.ziplongest
# import library
from itertools import zip_longest  
# initialising listoflist
test_list = [
   [('11'), ('12'), ('13')],
   [('21'), ('22'), ('23')],
   [('31'), ('32'), ('33')]
   ]
# printing intial list
print ("Initial List = ", test_list)  
# iterate list tuples list of list into single list
res_list = [item for my_list in zip_longest(*test_list)
for item in my_list if item]
# print final List
print ("Resultant List = ", res_list)
# using itertools.ziplongest + lambda + chain
# import library
from itertools import zip_longest, chain  
# initialising listoflist
test_list = [
   [('11'), ('12'), ('13')],
   [('21'), ('22'), ('23')],
   [('31'), ('32'), ('33')]
   ]
# printing intial list
print ("Initial List = ", test_list)  
# iterate list tuples list of list into single list
# using lambda + chain + filter
res_list = list(filter(lambda x: x, chain(*zip_longest(*test_list))))
# print final List
print ("Resultant List = ", res_list)
# list using list comprehension
# initialising listoflist
test_list = [
   [('11'), ('12'), ('13')],
   [('21'), ('22'), ('23')],
   [('31'), ('32'), ('33')]
]
# printing intial list
print ("Initial List = ", test_list)
# iterate list tuples list of list into single list
# using list comprehension
res_list = [item for list2 in test_list for item in list2]
# print final List
print ("Resultant List = ", res_list)