pythonic way to flatten nested lists? [duplicate] - python

This question already has answers here:
How do I make a flat list out of a list of lists?
(34 answers)
Apply function to each element of a list
(4 answers)
Closed 6 months ago.
I have a list-tuple-list tree and I'd like to flatten it for a query, so that I can print all the items of the the first lists of each tuple.
I can do it via a for loop:
bigNest = [([item1,item2],[]),([item3],[item4])]
mergedlist = []
for listItem in bigNest:
mergedlist += listItem[0]
print mergedList
Is there a simpler/quicker way which will also work with larger tuples?


edit: sorry the last post was wrong, you could do a list comprehension:
mergedlist = []
foovar = [mergedlist.extend(i[0]) for i in bigNest]

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Suppose I have two list of lists as follows:
List1=[[1,2],[3,4],[3,8]]
List2=[[1.2,2.4],[2.4,5.0],[4.5,6.0]]
How would I get the above as:
List3 = [{1:1.2,2:2.4},{3:2.4,4:5.0},{3:4.5,8:6.0}]

Try this:
List3 = [dict(zip(*lsts)) for lsts in zip(List1, List2)]

List1=[[1,2],[3,4],[3,8]]
List2=[[1.2,2.4],[2.4,5.0],[4.5,6.0]]
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for i,e in enumerate(List1):
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Python. Removing list from another list [duplicate]

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Remove all the elements that occur in one list from another
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Closed 1 year ago.
I have 2 lists
for i in range(1, 26):
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Use a list comprehension:
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This question already has answers here:
Get the first element of each tuple in a list in Python [duplicate]
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I have the following code which gives me list as shown below
listP= methodcall()
print(listP)
Output [('abcd',), ('efgh',)
How do I remove bracket,comma and single quotes?
I need below output:-
listP=['abcd','efgh']

This will do the work:
listp = [('abcd',), ('efgh',)]
listp = [l[0] for l in listp]
print(listp)
Take only first element from the tuples in the original list using list comprehension.

newlist = []
list1 = [('abcd',), ('efgh',)]
for elements in list1:
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list comprehension even list elements instead of loop and how to refer only to the index [duplicate]

This question already has answers here:
Shortest way to slice even/odd lines from a python array?
(4 answers)
Closed 3 years ago.
I want to use list comp' instead of a loop.
Let's sat I have a list of lists and I want only the even index elements.
Eg: [[a,a], [b,b], [c,c],[g,g]] to..... [[a,a], [c,c]]
This doesn't work
a = [i for i in the_list if i % 2 == 0)]

Here is a possible solution that keeps only lists with even indexes:
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Adding sublists into one list as lists elements in python [duplicate]

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Closed 4 years ago.
I'm looking for a way to sum up my output of list. I want to add each output of this for loop into one "big" list as a single list element.
for line in f.split('\n'):
words = line.split()
How do I achieve this:
L1 = [1,2,3]
L2 = [4,5,6]
L3 = [7,8,9]
SumList = [[1,2,3],[4,5,6],[7,8,9]]

You can append str.split list to another list
Ex:
res = []
for line in f.split('\n'):
res.append(line.split())
Or use list comprehension
Ex:
print([line.split() for line in f.split('\n')])

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