Python | Convert string tuples to list tuples
Last Updated : 28 Feb, 2023
Sometimes, while working with Python we can have a problem in which we have a list of records in form of tuples in stringified form and we desire to convert them to a list of tuples. This kind of problem can have its occurrence in the data science domain. Let’s discuss certain ways in which this task can be performed.
Method 1 (Using eval() + list comprehension): This problem can be easily performed as a one-liner using the inbuilt function of eval(), which performs this task of string to tuple conversion and list comprehension.
Python3
test_list = ["('gfg', 1)", "('is', 2)", "('best', 3)"]
print("The original list is : " + str(test_list))
res = [eval(ele) for ele in test_list]
print("The list tuple after conversion : " + str(res))
|
Output : The original list is : ["('gfg', 1)", "('is', 2)", "('best', 3)"] The list tuple after conversion : [('gfg', 1), ('is', 2), ('best', 3)] Time complexity: O(n), where n is the length of the input list.
Auxiliary space: O(n), as we are creating a new list with the same length as the input list.
Method 2 (Using eval() + map()): This task can also be performed using a combination of the above functions. The task performed by list comprehension above can be performed using a map() in this method.
Python3
test_list = ["('gfg', 1)", "('is', 2)", "('best', 3)"]
print("The original list is : " + str(test_list))
res = list(map(eval, test_list))
print("The list tuple after conversion : " + str(res))
|
Output : The original list is : ["('gfg', 1)", "('is', 2)", "('best', 3)"] The list tuple after conversion : [('gfg', 1), ('is', 2), ('best', 3)] Time Complexity: O(n), where n is the number of elements in the input list.
Auxiliary Space: O(n), where n is the number of elements in the input list, for the output list.
Method 3: Using the enumerate function
Python3
s=["('gfg', 1)", "('is', 2)", "('best', 3)"]
x= [eval(i) for a,i in enumerate(s)]
print(x)
|
Output [('gfg', 1), ('is', 2), ('best', 3)] Time complexity: O(n), where n is the length of the list ‘s’.
Auxiliary space: O(n), where n is the length of the list ‘s’.
Method 4: Using map()+eval()
Python3
s=["('gfg', 1)", "('is', 2)", "('best', 3)"]
x=list(map(eval,s))
print(x)
|
Output [('gfg', 1), ('is', 2), ('best', 3)] The time complexity of the program is O(n), where n is the length of the list “s”.
The auxiliary space complexity of the program is also O(n), as the list “x” has to store n elements, where n is the length of the input list “s”.
Method#5: Using Regex method.
Python3
import re
test_list = ["('gfg', 1)", "('is', 2)", "('best', 3)"]
print("The original list is : " + str(test_list))
res = [tuple(map(int, re.findall(r'\d+', i))) if j.isdigit() else (j.strip("(')"), int(k)) for i in test_list for j, k in re.findall(r"\('(.*?)', (.*?)\)", i)]
print("The list tuple after conversion : " + str(res))
|
Output The original list is : ["('gfg', 1)", "('is', 2)", "('best', 3)"] The list tuple after conversion : [('gfg', 1), ('is', 2), ('best', 3)] Time Complexity: O(n)
Auxiliary Space: O(n)
Method 6: (Using ast.literal_eval() instead of eval())
The ast module provides a safer way to evaluate string literals. The ast.literal_eval() function can evaluate a string containing a Python expression or a container object literal and return the corresponding object. It only evaluates literals, so it won’t execute arbitrary code like eval().
Python3
import ast
test_list = ["('gfg', 1)", "('is', 2)", "('best', 3)"]
print("The original list is : " + str(test_list))
res = [ast.literal_eval(ele) for ele in test_list]
print("The list tuple after conversion : " + str(res))
|
Output The original list is : ["('gfg', 1)", "('is', 2)", "('best', 3)"] The list tuple after conversion : [('gfg', 1), ('is', 2), ('best', 3)] Time Complexity: O(n)
Auxiliary Space: O(n)
Similar Reads
Python | Convert String to tuple list
Sometimes, while working with Python strings, we can have a problem in which we receive a tuple, list in the comma-separated string format, and have to convert to the tuple list. Let's discuss certain ways in which this task can be performed. Method #1 : Using loop + split() + replace() This is a br
5 min read
Python - Convert Tuple String to Integer Tuple
Interconversion of data is a popular problem developer generally deal with. One can face a problem to convert tuple string to integer tuple. Let's discuss certain ways in which this task can be performed. Method #1 : Using tuple() + int() + replace() + split() The combination of above methods can be
7 min read
Python | Convert String to list of tuples
Sometimes, while working with data, we can have a problem in which we have a string list of data and we need to convert the same to list of records. This kind of problem can come when we deal with a lot of string data. Let's discuss certain ways in which this task can be performed. Method #1: Using
8 min read
Convert tuple to string in Python
The goal is to convert the elements of a tuple into a single string, with each element joined by a specific separator, such as a space or no separator at all. For example, in the tuple ('Learn', 'Python', 'Programming'), we aim to convert it into the string "Learn Python Programming". Let's explore
3 min read
Convert String to Tuple - Python
When we want to break down a string into its individual characters and store each character as an element in a tuple, we can use the tuple() function directly on the string. Strings in Python are iterable, which means that when we pass a string to the tuple() function, it iterates over each characte
2 min read
Python - Convert String Records to Tuples Lists
Sometimes, while working with data, we can have problem in which we need to convert the data list which in string format to list of tuples. This can occur in domains in which we have cross type inputs. Lets discuss certain ways in which this task can be performed. Method #1 : Using loop + eval() The
7 min read
Python - Convert Tuple to Tuple Pair
Sometimes, while working with Python Tuple records, we can have a problem in which we need to convert Single tuple with 3 elements to pair of dual tuple. This is quite a peculiar problem but can have problems in day-day programming and competitive programming. Let's discuss certain ways in which thi
10 min read
Convert List Of Tuples To Json String in Python
We have a list of tuples and our task is to convert the list of tuples into a JSON string in Python. In this article, we will see how we can convert a list of tuples to a JSON string in Python. Convert List Of Tuples To Json String in PythonBelow, are the methods of Convert List Of Tuples To Json St
3 min read
Python | Convert mixed data types tuple list to string list
Sometimes, while working with records, we can have a problem in which we need to perform type conversion of all records into a specific format to string. This kind of problem can occur in many domains. Let's discuss certain ways in which this task can be performed. Method #1 : Using list comprehensi
5 min read
Convert String List to ASCII Values - Python
We need to convert each character into its corresponding ASCII value. For example, consider the list ["Hi", "Bye"]. We want to convert it into [[72, 105], [66, 121, 101]], where each character is replaced by its ASCII value. Let's discuss multiple ways to achieve this. Using List Comprehension with
3 min read