Python UnboundLocalError error while executing script

Question

Hi,

Below is the code i am trying but is showing error, please help with this code.

word = []
def letter(a):
for each in a:
if each.isalpha():
word = word+1
word.append
else:
digit = digit+1
digit.append

#letter(input("The letter with digit : "))
letter("Hello123")
print(word)

Error:

Traceback (most recent call last):

File "", line 13, in 
letter("Hello123")

File "", line 5, in letter
word = word+1

UnboundLocalError: local variable "word" referenced before assignment

Answer 1

The reason for this error is that the variables word and digit are not accessible inside the function. To overcome the issue you are facing, you need to declare the variables - word, digit as global. Also, define the variables as an integer instead of list as they just store the number of characters and digits in the given string.

Try the below modified Python code and check:

word=0

digit=0

def letter(a):

    global word

    global digit

    for each in a:

        if each.isalpha():

            word=word+1

        else:

            digit=digit+1

#letter(input("The letter with digit : "))

letter("Hello123")

print(word)

Answer 2

Inside your function when you say word=word+1, actually the word variable after the equal sign won't be found since you are altering it already in the expression assignee. To overcome this issue there are two solutions, you either use global (which is not recommended) or first try to save the word and digit value in local variables then use them in your expression, see below sample code:

^{word=0
digit=0}

^{def letter(a):
    w = word
    d = digit
    for each in a:
        if each.isalpha():
            w=w+1
        else:
            d=d+1
    return w,d
word, digit = letter("Hello123")
print(word,digit)}

This could be confusing at start, perhaps you need to read about variable scopes in Python.