import sys
def encrypt(k):
plaintext = raw_input('Enter plain text message: ')
cipher = ''
for each in plaintext:
c = (ord(each)+k) % 126
if c < 32:
c+=31
cipher += chr(c)
print 'Your encrypted message is: ' + cipher
def decrypt(k):
cipher = raw_input('Enter encrypted message: ')
plaintext = ''
for each in cipher:
p = (ord(each)-k) % 126
if p < 32:
p+=95
plaintext += chr(p)
print 'Your plain text message is: ' + plaintext
def main(argv):
if (len(sys.argv) != 3):
sys.exit('Usage: ceaser.py <k> <mode>')
if sys.argv[2] == 'e':
encrypt(int(sys.argv[1]))
elif sys.argv[2] == 'd':
decrypt(int(sys.argv[1]))
else:
sys.exit('Error in mode type')
if __name__ == "__main__":
main(sys.argv[1:])
