Chap5Q9.py

def func_start_A(l): # function to count lines starting with ‘A’
    c = 0 # c is the count of such lines
    for line in l:
        if line.startswith('A'):
            c += 1
            return c

f1 = open('LINES.txt', 'r')
l = f1.readlines() # creates a list of all the lines in the file
print('Number of lines starting with A in the file LINES.txt is', func_start_A(l))