Teaching Fatima fundamental file operations in Python

cp.py

# Simple version of cp command

import sys

if len(sys.argv) < 3:
    raise Exception('too few arguments')

command, source, destination, *rest = sys.argv

with open(source, 'rb') as source_file:
    with open(destination, 'wb') as destination_file:
        while current_chunk := source_file.read(4096):
            destination_file.write(current_chunk)

general_file_operations.py

# open() - modes: r, w, r+, a, x, b
our_family = open('family.log', 'w')

# write() to file
our_family.write('Khety\n')
our_family.write('Maxwell\n')
our_family.write('????\n')

# close()
our_family.close()

# Reopen, in read mode!
our_family = open('family.log', 'r')

# read()
family = our_family.read()


print(family)

our_family.seek(3)

print(f'here is our family, again: {our_family.read()}')

our_family.close()

# using contexts, it will call close
# at the end of the block
print('use with to not need close()')
with open('family.log', 'r') as famlog:
    print(famlog.read())

print('loop through lines')
# loop through lines of a text file
with open('family.log', 'r') as famlog:
    for line in famlog:
        print(f'current line: {line}')

# read x characters
print('print first x chars')
with open('family.log', 'r') as famlog:
    print(famlog.read(10))