Python | Convert key-value pair comma separated string into dictionary

Given a string, with different key-value pairs separated with commas, the task is to convert that string into the dictionary. These types of problems are common in web development where we fetch arguments from queries or get a response in the form of strings. Given below are a few methods to solve the task. 

Method #1: Using dictionary comprehension

Python3

# Python3 code to demonstrate
# converting comma separated string
# into dictionary

# Initialising string
ini_string1 = 'name = akshat, course = btech, branch = computer'

# Printing initial string
print("Initial String", ini_string1)

# Converting string into dictionary
# using dict comprehension
res = dict(item.split("=") for item in ini_string1.split(", "))

# Printing resultant string
print("Resultant dictionary", str(res))

Output

Initial String name = akshat, course = btech, branch = computer
Resultant dictionary {'name ': ' akshat', 'course ': ' btech', 'branch ': ' computer'}

Time Complexity: O(n)
Auxiliary Space: O(n)

Method #2: Using Map and lambda

Python3

# Python3 code to demonstrate
# converting comma separated string
# into dictionary

# Initialising string
ini_string1 = 'name = akshat, course = btech, branch = computer'

# Printing initial string
print("Initial String", ini_string1)

# Converting string into dictionary
# using map and lambda
res = dict(map(lambda x: x.split('='), ini_string1.split(', ')))

# Printing resultant string
print("Resultant dictionary", str(res))

Output

Initial String name = akshat, course = btech, branch = computer
Resultant dictionary {'name ': ' akshat', 'course ': ' btech', 'branch ': ' computer'}

Time Complexity: O(n)
Space Complexity: O(n)

Method #3: Using eval() function

Python3

# Python3 code to demonstrate
# converting comma separated string
# into dictionary

# Initialising string
ini_string1 = 'name ="akshat", course ="btech", branch ="computer"'

# Printing initial string
print("Initial String", ini_string1)

# Converting string into dictionary
# using eval
res = eval('dict('+ini_string1+')')

# Printing resultant string
print("Resultant dictionary", str(res))

Output

Initial String name ="akshat", course ="btech", branch ="computer"
Resultant dictionary {'name': 'akshat', 'course': 'btech', 'branch': 'computer'}

Time Complexity: O(n)
Space Complexity: O(n)

Method #4 : Using split() and index() methods

Python3

# Python3 code to demonstrate
# converting comma separated string
# into dictionary

# Initialising string
ini_string1 = 'name = akshat, course = btech, branch = computer'

# Printing initial string
print("Initial String", ini_string1)

# Converting string into dictionary
res = dict()
x = ini_string1.split(",")
for i in x:
    a = i[:i.index("=")]
    b = i[i.index("=")+1:]
    res[str(a)] = str(b)
# Printing resultant string
print("Resultant dictionary", str(res))

Output

Initial String name = akshat, course = btech, branch = computer
Resultant dictionary {'name ': ' akshat', ' course ': ' btech', ' branch ': ' computer'}

Time Complexity: O(n)
Space Complexity: O(n)