Sometimes, while working with data in form of records, we can have a problem in which we need to concatenate elements of all the records received. This is a very common application that can occur in Data Science domain. Let’s discuss certain ways in which this task can be performed.
Method #1: Using generator expression + join() This is the most basic method to achieve solution to this task. In this, we iterate over whole nested lists using generator expression and get the concatenated elements using join().
# Python3 code to demonstrate working of# Concatenate All Records# using join() + generator expression# initialize listtest_list = [('geeksforgeeks ', 'is'), (' best', ' for'), (' all', ' geeks')]
# printing original listprint("The original list : " + str(test_list))
# Concatenate All Records# using join() + generator expressionres = "".join(j for i in test_list for j in i)
# printing resultprint("The Concatenated elements of list is : " + res)
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The original list : [('geeksforgeeks ', 'is'), (' best', ' for'), (' all', ' geeks')]
The Concatenated elements of list is : geeksforgeeks is best for all geeks
Time Complexity: O(n) where n is the number of tuples in the list.
Auxiliary Space: O(1) as only a few variables are used.
Method #2 : Using join() + map() + chain.from_iterable() The combination of above methods can also be used to perform this task. In this, the extension of concatenation is done by combination of map() and from_iterable().
# Python3 code to demonstrate working of# Concatenate All Records# using join() + map() + chain.from_iterable()from itertools import chain
# initialize listtest_list = [('geeksforgeeks ', 'is'), (' best', ' for'), (' all', ' geeks')]
# printing original listprint("The original list : " + str(test_list))
# Concatenate All Records# using join() + map() + chain.from_iterable()res = "".join(map(str, chain.from_iterable(test_list)))
# printing resultprint("The Concatenated elements of list is : " + str(res))
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The original list : [('geeksforgeeks ', 'is'), (' best', ' for'), (' all', ' geeks')]
The Concatenated elements of list is : geeksforgeeks is best for all geeks
Time Complexity: O(n), where n is the total number of characters in all the tuples in the list.
Auxiliary Space: O(n), as we are using an additional string to store the concatenated result.
Method #3 : Using extend() and join() methods
# Python3 code to demonstrate working of# Concatenate All Records# initialize listtest_list = [('geeksforgeeks ', 'is'), (' best', ' for'), (' all', ' geeks')]
# printing original listprint("The original list : " + str(test_list))
# Concatenate All Recordsx = []
for i in test_list:
x.extend(list(i))
res = " ".join(x)
# printing resultprint("The Concatenated elements of list is : " + res)
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The original list : [('geeksforgeeks ', 'is'), (' best', ' for'), (' all', ' geeks')]
The Concatenated elements of list is : geeksforgeeks is best for all geeks
Time complexity: O(n), where n is the total number of elements in the list.
Auxiliary space: O(n), where n is the total number of elements in the list.
Method #4 : Using reduce() + join()
from functools import reduce
# initialize listtest_list = [('geeksforgeeks ', 'is'), (' best', ' for'), (' all', ' geeks')]
# printing original listprint("The original list : " + str(test_list))
# Concatenate All Recordsresult = " ".join(reduce(lambda x, y: x+y, test_list))
# printing resultprint("The Concatenated elements of list is : " , result)
#This code is contributed by Edula Vinay Kumar Reddy |
The original list : [('geeksforgeeks ', 'is'), (' best', ' for'), (' all', ' geeks')]
The Concatenated elements of list is : geeksforgeeks is best for all geeks
Time complexity: O(n), where n is the length of the list.
Auxiliary space: O(n)
Method #5: Using a loop to concatenate the elements
The program initializes a list of tuples and prints the original list. Then, it loops through each tuple and concatenates all the elements of each tuple to a single string variable called “res”. Finally, it prints the concatenated result.
# Python3 code to demonstrate working of# Concatenate All Records# using a loop# initialize listtest_list = [('geeksforgeeks ', 'is'), (' best', ' for'), (' all', ' geeks')]
# printing original listprint("The original list : " + str(test_list))
# Concatenate All Records# using a loopres = ''
for i in test_list:
for j in i:
res += j
# printing resultprint("The Concatenated elements of list is : " + res)
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The original list : [('geeksforgeeks ', 'is'), (' best', ' for'), (' all', ' geeks')]
The Concatenated elements of list is : geeksforgeeks is best for all geeks
Time complexity: O(n^2), where n is the number of tuples in the list.
Auxiliary space: O(n^2), since the concatenated string ‘res’ is built up by appending each element of each tuple, resulting in a string of length proportional to the number of tuples and the length of each tuple.
Method #6: Using list comprehension and join()
Step-by-step approach:
- Initialize the list of tuples.
- Use a list comprehension to iterate through each tuple in the list and join its elements using the join() method.
- Join the resulting list of strings using the join() method to obtain the final concatenated string.
# Python3 code to demonstrate working of# Concatenate All Records# using list comprehension and join()# initialize listtest_list = [('geeksforgeeks ', 'is'), (' best', ' for'), (' all', ' geeks')]
# printing original listprint("The original list : " + str(test_list))
# Concatenate All Records# using list comprehension and join()res = ''.join([''.join(t) for t in test_list])
# printing resultprint("The Concatenated elements of list is : " + res)
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The original list : [('geeksforgeeks ', 'is'), (' best', ' for'), (' all', ' geeks')]
The Concatenated elements of list is : geeksforgeeks is best for all geeks
Time complexity: O(n), where n is the total number of characters in all the tuples.
Auxiliary space: O(n), where n is the total number of characters in all the tuples, because we are creating a new list of concatenated strings.