Say if
list1 = ['apple', 'orange', 'grape']
list2 = ['pineapple', 'banana', 'pear']
how could you add them so that
list3 = ['apple pineapple', 'orange banana', 'grape pear']
Using a for statement inside a for statement I can get this out:
applepineapple
applebanana
applepear
orangepineapple
orangebanana
orangepear
grapepineapple
grapebanana
grapepear
Thanks!
There are many ways to do this. One way is a list comprehension with zip:
>>> zip(list1, list2)
[('apple', 'pineapple'), ('orange', 'banana'), ('grape', 'pear')]
>>> ['{} {}'.format(x, y) for x, y in zip(list1, list2)]
['apple pineapple', 'orange banana', 'grape pear']
You can also use concatenation (x + ' ' + y) or interpolation ('%s %s' % (x, y)) to form the strings.
>>> list1 = ['apple', 'orange', 'grape']
>>> list2 = ['pineapple', 'banana', 'pear']
>>> [ list1[x]+ " " +list2[x] for x in range(len(list1))] # both should must have same length
['apple pineapple', 'orange banana', 'grape pear']
pythonic way:
>>> map(" ".join,zip(list1,list2))
['apple pineapple', 'orange banana', 'grape pear']
print ([' '.join(z) for z in zip(list1,list2)])
You can do it in one line with:
new_list = map(lambda x : x[0]+' '+x[1], zip(list1, list2))
zip() takes two sequences and forms list where the i-th entry is a tuple containing the i-th entry of the first list and the i-th entry of the second list. map(func, sequence) applies a given function to a sequence. These two commands will save you a ton of time working with lists.
ith element of both lists.