ungleich-learning-circle/youngjin.han/python-the-hard-way/ex20.py

36 lines
1021 B
Python

from sys import argv # import argv
script, input_file = argv # define argv
def print_all(f): # define a function
print(f.read()) # print all
def rewind(f): # define a function
f.seek(0) # jump the starting point of a file
def print_a_line(line_count, f): # define a function
print(line_count, f.readline()) # pinrt a line on the file
current_file = open(input_file) # open a file
print("First let's print the whole file:\n") # print a script
print_all(current_file) # call the function
print("Now let's rewind, kind of like a tape.") # print a script
rewind(current_file) # call the function
print("Let's print three lines:") # print a script
current_line = 1 # define a value
print_a_line(current_line, current_file) # call the function
#current_line = current_line + 1 # define a value
current_line += 1
print_a_line(current_line, current_file) # call the function
#current_line = current_line + 1 # define a value
current_line += 1
print_a_line(current_line, current_file) # call the function