from sys import argv
script, input_file = argv
def print_all(f):
print(f.read())
def rewind(f):
f.seek(0)
def print_a_line(line_count, input_file):
print(line_count, input_file.readline())
current_file = open(input_file)
print ("First let's print the whole file:/n")
print_all(current_file)
print("Now let's rewind, kind of like a tape.")
rewind(current_file)
print("Let's print three lines:")
current_line = 1
print_a_line(current_line, current_file)
current_line = current_line + 1
print_a_line(current_line, current_file)
current_line = current_line + 1
print_a_line(current_line, current_file)
output
D:\>python ex20.py ex20.txt
First let's print the whole file:/n
We can just give the function numbers directly:
You have 20 cheeses!
You have 30 boexes of crackers!
Man that's enough for a party!
Get a blanke.
Or, we can use variables from our script:
You have 10 cheeses!
You have 50 boexes of crackers!
Man that's enough for a party!
Get a blanke.
We can even do math inside too:
You have 30 cheeses!
You have 11 boexes of crackers!
Man that's enough for a party!
Get a blanke.
And we can combine the two, variables and math:
You have 110 cheeses!
You have 1050 boexes of crackers!
Man that's enough for a party!
Get a blanke.
Now let's rewind, kind of like a tape.
Let's print three lines:
1 We can just give the function numbers directly:
2 You have 20 cheeses!
3 You have 30 boexes of crackers!
2019-09-29
04:22:43