Python - Convert delimiter separated Mixed String to valid List

Python – Convert delimiter separated Mixed String to valid List

Last Updated : 19 May, 2021

Given a string with elements and delimiters, split elements on delimiter to extract with elements ( including containers).

Input : test_str = “6*2*9*[3, 5, 6]*(7, 8)*8*4*10”, delim = “*”
Output : [6, 2, 9, [3, 5, 6], (7, 8), 8, 4, 10]
Explanation : Containers and elements separated using *.
Input : test_str = “[3, 5, 6]*(7, 8)*8*4*10”, delim = “*”
Output : [[3, 5, 6], (7, 8), 8, 4, 10]
Explanation : Containers and elements separated using *.

Method #1 : Using loop + eval() + split()

This is one way in which this task can be done. In this the separation is done using split() and eval() does the important task of performing evaluation of data types to be containers or simpler elements.

Python3

# Python3 code to demonstrate working of
# Convert delimiter separated Mixed String to valid List
# Using loop + split() + eval()
 
# initializing string
test_str = "6# 2# 9#[3, 5, 6]#(7, 8)# 8# 4# 10"
 
# printing original string
print("The original string is : " + str(test_str))
 
# initializing delim
delim = "#"
 
# spliting using split()
temp = test_str.split(delim)
res = []
 
# using loop + eval() to convert to
# required result
for ele in temp:
  res.append(eval(ele))
 
# printing result
print("List after conversion : " + str(res))

Output

The original string is : 6#2#9#[3, 5, 6]#(7, 8)#8#4#10
List after conversion : [6, 2, 9, [3, 5, 6], (7, 8), 8, 4, 10]

Method #2 : Using eval() + split() + list comprehension

This is yet another way in which this task can be performed. In this, we perform similar task as above method. The only difference being that entire logic is encapsulated as one liner using list comprehension.

Python3

# Python3 code to demonstrate working of
# Convert delimiter separated Mixed String to valid List
# Using eval() + split() + list comprehension
 
# initializing string
test_str = "6# 2# 9#[3, 5, 6]#(7, 8)# 8# 4# 10"
 
# printing original string
print("The original string is : " + str(test_str))
 
# initializing delim
delim = "#"
 
# encapsulating entire result in list comprehension
res = [eval(ele) for ele in test_str.split(delim)]
 
# printing result
print("List after conversion : " + str(res))

Output

The original string is : 6#2#9#[3, 5, 6]#(7, 8)#8#4#10
List after conversion : [6, 2, 9, [3, 5, 6], (7, 8), 8, 4, 10]

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