CODEWITHSUNDEEP
pythonpython-3.xlist
Ahmad Aziz
Ahmad Aziz

Reputation: 9

Merging first element in sublist with elements in the same list using python

I have a list below. I need to use it to create a new nested list with only the first element in the sublist with the last element in list. 

a=[[a,b,c],3]

the outcome should look like

b=[[a,3],[b,3],[c,3]]

Upvotes: 0

Views: 65

Answers (2)

Kasravnd
Kasravnd

Reputation: 107287

Use zip():

In [79]: a=[['a','b','c'],3]

In [80]: list(zip(a[0], [a[1]]*len(a[0])))
Out[80]: [('a', 3), ('b', 3), ('c', 3)]

Or:

In [83]: (a, b, c), num = a

In [84]: [(a, num), (b, num), (c, num)]
Out[84]: [('a', 3), ('b', 3), ('c', 3)]

Or more general:

In [85]: lst, num = a

In [86]: from itertools import repeat

In [87]: list(zip(lst, repeat(num, len(lst))))
Out[87]: [('a', 3), ('b', 3), ('c', 3)]

Another way is using a nested list comprehension:

In [15]: a
Out[15]: [['a', 'b', 'c'], [1, 2]]

In [16]: [(j, i) for i in a[1] for j in a[0]]
Out[16]: [('a', 1), ('b', 1), ('c', 1), ('a', 2), ('b', 2), ('c', 2)]

Upvotes: 1

Aran-Fey
Aran-Fey

Reputation: 43126

You can use a list comprehension:

>>> a = [['a','b','c'], 3]
>>> sublist, value = a
>>> [[x, value] for x in sublist]
[['a', 3], ['b', 3], ['c', 3]]

Upvotes: 1

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