Written in pep$8$ and as a stack please help me Write pep$8$ programs to do the following.

$1.$ Input a number and output the number of digits that are $7.$ The input number will be followed by # $($so you will know that is the end of the number. Here is some sample input and output:

$77273$# There are $3$ sevens

$8923$# There are $0$ sevens

$177$# There are $2$ sevens

Hint: You will find this easier if you treat the input as all characters. fix my code so it produces the right format of the output