Counting Duplicates

DESCRIPTION:
Count the number of Duplicates
Write a function that will return the count of distinct case-insensitive alphabetic characters and numeric digits that occur more than once in the input string. The input string can be assumed to contain only alphabets (both uppercase and lowercase) and numeric digits.

Example:

"abcde" -> 0 # no characters repeats more than once
"aabbcde" -> 2 # 'a' and 'b'
"aabBcde" -> 2 # 'a' occurs twice and 'b' twice (`b` and `B`)
"indivisibility" -> 1 # 'i' occurs six times
"Indivisibilities" -> 2 # 'i' occurs seven times and 's' occurs twice
"aA11" -> 2 # 'a' and '1'
"ABBA" -> 2 # 'A' and 'B' each occur twice

Solution- ###Python

def duplicate_count(text):
    if len(text) == 0:
        return 0
    text=text.lower()
    count=0
    for i in set(text):
        if text.count(i)>1:
            count +=1
    return count

Comments

[Sophist]

How about:

def duplicate_count(text):
    if len(text) == 0:
        return 0
    text=text.lower()
    return sum(map(lambda x: text.count(x) > 1,set(text)))

[Lancelot03]

It was good but difficult to understand for beginners.

[Farrukh]

Hi...do u know ML programming ?

[Lancelot03]

Yhaa I right now learning Machine Learning with python