Python | Converting String content to dictionary

Sometimes, we are fed with string and we may have to convert it’s content to dictionary. The string may have a specified format that could be key-value convertible. This type of problem is quite common in Machine Learning domain. Let’s discuss certain ways in which this problem can be solved. 

Method #1 : Using split() + dictionary comprehension The combination of above method can be used to perform this particular task. This is 2 process method. In 1st step, the string is converted to list using split and then converted back to dictionary using dictionary comprehension. 

Python3

# Python3 code to demonstrate working of
# Converting String content to dictionary
# Using dictionary comprehension + split()

# initializing string
test_str = "Gfg = 1, Good = 2, CS = 3, Portal = 4 "

# printing original string
print("The original string is : " + test_str)

# Using dictionary comprehension + split()
# Converting String content to dictionary
res = {key: int(val) for key, val in (item.split('=')
                                      for item in test_str.split(', '))}

# printing result
print("The newly created dictionary : " + str(res))

Output

The original string is : Gfg = 1, Good = 2, CS = 3, Portal = 4 
The newly created dictionary : {'Gfg ': 1, 'Good ': 2, 'CS ': 3, 'Portal ': 4}

Time complexity: O(n*n), where n is the number of key-value pairs in the dictionary.
Auxiliary space: O(n), to store the keys and values in dictionary.

Method #2 : Using eval() This particular problem can be solved using the inbuilt function eval which internally evaluates the string and converts the string to dictionary depending upon the condition. 

Python3

# Python3 code to demonstrate working of
# Converting String content to dictionary
# Using eval()

# initializing string
test_str = "Gfg = 1, Good = 2, CS = 3, Portal = 4"

# printing original string
print("The original string is : " + test_str)

# Using eval()
# Converting String content to dictionary
res = eval('dict(% s)' % test_str)

# printing result
print("The newly created dictionary : " + str(res))

Output

The original string is : Gfg = 1, Good = 2, CS = 3, Portal = 4
The newly created dictionary : {'Gfg': 1, 'Good': 2, 'CS': 3, 'Portal': 4}

Method #3 : Using split(),index() and slicing

Python3

# Python3 code to demonstrate working of
# Converting String content to dictionary

# initializing string
test_str = "Gfg = 1, Good = 2, CS = 3, Portal = 4"

# printing original string
print("The original string is : " + test_str)

res = dict()
x = test_str.split(",")
for i in x:
    a = i[:i.index("=")]
    b = i[i.index("=")+1:]
    res[a] = b
# printing result
print("The newly created dictionary : " + str(res))

Output

The original string is : Gfg = 1, Good = 2, CS = 3, Portal = 4
The newly created dictionary : {'Gfg ': ' 1', ' Good ': ' 2', ' CS ': ' 3', ' Portal ': ' 4'}