function to find the number of occurrences of '2' in first 'n' numbers.

python_intro.py

#one easy solution:

def get_digit_count(n):
    count = 0
    for numbers in range(n): 
        count = count + str(numbers).count('2')
    return count


# in the above program:
# 'def' defines a function. so we can call later like 'get_digit_count(1000)'
# 'range' is a python function that gives a list of numbers.        
# range(5) = [0, 1, 2, 3, 4]

# one liner solution:
sum(str(numbers).count('2') for numbers in range(n))
# we can explain this later step by step