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TypeError: String Indices Must be Integers

Updated May 05, 2020

TypeError: String Indices Must be Integers

All the characters of a string have a unique index. This index specifies the position of each character of the string. But you have to remember that all the indexes are integers. When you specify a string or a float as the index, you will encounter an error called TypeError: String Indices Must be Integers. You have to always assign an integer value to the indices.

print(mystring['first'])

print(mystring[1.2])

Error Example

# Python3 code example

# Initializing string with name mystring
mystring = 'Hello Stechies'

print(mystring['first'])

Output:

Traceback (most recent call last):
  File "string-integers.py", line 6, in <module>
    print(mystring['first'])
TypeError: string indices must be integers json.

When we initializing a string, it starts indexing each character of the string. In the above code example, we are trying to print the value of the first index or character of a string name “mystring” by setting the first index as ‘first’

As we already know that the value of the index is always an integer, not a character this is the reason we get this error ‘string indices must be integers’.

TypeError: String Indices Must be Integers

Correct example:

# Python3 code example

# Initializing string with name mystring
mystring = 'Hello Stechies'

print('Output: ' + mystring[1])

Output:

Output: e

Explanation:
In the above example first, we initialized a string ‘mystring’. Then we accessed the character at index ‘1’ bypassing ‘1’ as a parameter of the string. Here we did not encounter any error because the string indices are provided an integer value instead of a string. 

Error: typeerror string indices must be integers not float

This type of error occurs when we set ‘float’ value of the first index instead of an ‘integer’ while initializing a string.

Error Example

# Python3 code example

# Initializing string with name mystring
mystring = 'Hello Stechies'

print(mystring[4.2])

Output:

Traceback (most recent call last):
  File "string-integers.py", line 6, in <module>
    print(mystring[4.2])
TypeError: string indices must be integers not float

Explanation:
In the above example, we provided a float value to the string indices at line 6 “mystring[4.2]” of the code.
 But we know that the string indices only accepts integer value. Thus the error “TypeError: String indices must be integers not float” is raised. 

Correct example

# Python3 code example

# Initializing string with name mystring
mystring = 'Hello Stechies'

print('Output: ' + mystring[4])

Output:

Output: o

Explanation:
In the above example, instead of providing the float value to the string indices, we provided an integer value at line 6 “mystring[4.]” of the code. Thus no error is encountered. Since string indices only accept integer value.

Conclusion

So if you encounter the TypeError, check the type of indices that you have already mentioned. Always make sure that the first index and the rest are integers. 


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