How to Merge Multiple Lists into One List in Python

join list of lists in python

import itertools
a = [['a','b'], ['c']]
print(list(itertools.chain.from_iterable(a)))

This gives

['a', 'b', 'c']

Combine multiple lists into a single list

You were asked to zip the three lists:

people = list(zip(names, heights, weights))

How to merge multiple lists into 1 but only those elements that were in all of the initial lists?

Given some lists xs1, ..., xs5:

xss = [xs1, xs2, xs3, xs4, xs5]
sets = [set(xs) for xs in xss]
merged = set.intersection(*sets)

This has the property that merged may be in any order.

How do I concatenate two lists in Python?

Use the + operator to combine the lists:

listone = [1, 2, 3]
listtwo = [4, 5, 6]

joinedlist = listone + listtwo

Output:

>>> joinedlist
[1, 2, 3, 4, 5, 6]

merge multiple lists into one list in python using for loop

1. No need for using grouped_df.colums; a dataframe iterates over columns anyway:

   for x in grouped_df:
   

2. In your for loop you every time cleared your list mx; you probably want to clear it only once, i.e. before your for loop:

   mx = []
   for x in grouped_df:
   

3. In your for loop you every time print your list mx (freshly cleared and appended with only one — the current — element).
   
   You probably want to print it only once, after all elements will be appended, i.e. after your loop.

So your corrected code should be:

mx = []
for x in grouped_df:
    maxvalue = grouped_df[x].max() 
    mx.append(maxvalue)
print(mx)

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Note:

Manually iterating over data in pandas is always suspicious — generally, there is often a more elegant “pandasonic” solution.

In your case you may simply print

list(grouped_df.max())

or

grouped_df.max().to_list()

(grouped_df.max() is a series, the list() function or the .to_list() method makes a list from it.)

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