python how to concatenate lists code example

Example 1: how to combine two lists in python

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

joinedlist = listone + listtwo

Example 2: python how to add one list to another list

# Basic syntax:
first_list.append(second_list) # Append adds the the second_list as an
#	element to the first_list
first_list.extend(second_list) # Extend combines the elements of the 
#	first_list and the second_list

# Note, both append and extend modify the first_list in place

# Example usage for append:
first_list = [1, 2, 3, 4, 5]
second_list = [6, 7, 8, 9]
first_list.append(second_list)
print(first_list)
--> [1, 2, 3, 4, 5, [6, 7, 8, 9]]

# Example usage for extend:
first_list = [1, 2, 3, 4, 5]
second_list = [6, 7, 8, 9]
first_list.extend(second_list)
print(first_list)
--> [1, 2, 3, 4, 5, 6, 7, 8, 9]

Example 3: add two list in python

list1 = ["a", "b" , "c"]
list2 = [1, 2, 3]

list1.extend(list2)
print(list1)

Example 4: join lists python

first_list = ["1", "2"]
second_list = ["3", "4"]

# Multiple ways to do this:
first_list += second_list
first_list = first_list + second_list
first_list.extend(second_list)

Example 5: merge lists in list python

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

Example 6: python concatenate list of lists

x = [["a","b"], ["c"]]

result = sum(x, [])

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