1. Decimal to Hexadecimal Digit Conversion
#
# Name:
# File:
DigitConversionSp08.py
# Date: January 30, 2008
#
# Desc: Converts Decimal Digits to Hexadecimal
#
def
main():
# Display Title
print
print "Decimal to Hexadecimal Digit
Conversion"
print
# Use a string to list the hexadecimal
digits
hexDigits =
"0123456789ABCDEF"
# Get
decimal value
n = input("Enter
a decimal digit between 0 and 15: ");
# look up
hex value and display it
print
print n, "=", hexDigits[n]
print
main()
2. Caesar Cipher Program
#
# Name:
# File: CaesarCipher.py
# Date: January 30, 2008
#
# Desc: An implementation
of the Caesar cipher
#
def main():
# Display Program Title
print
print
"Caesar Cipher Program"
print
# Get Plain Text String and Numeric Key
str1 = raw_input("Enter
plain text to encode: ")
key = input("Enter key: ")
# Generate Cipher Text String
str2 =
"" # initialize cipher
text str to empty
for i in range(len(str1)):
a = (ord(str1[i])- ord("A")) # Convert letter to
integer value
# between 0 and 25
b =((a + key) % 26)
# Apply numeric key
c = chr(b +
65) # Convert integer to ASCII char
str2 =
str2 + c # concatenate to cipher text string
#
Display Cipher Text String
print
print
"Cipher text:", str2
#
Decode Cipher Text
reversedKey = 26 - key # adding
26 - key is equivalent
# to subtracting key
str3 =
"" # initialize decoded
text string
for i in range(len(str2)):
a = (ord(str2[i])- ord("A")) # letter ->
range(25)
b =((a + reversedKey) % 26) # apply reversed
numeric key
c = chr(b +
65) # convert to ASCII character
str3 =
str3 + c # concatenate to decoded string
#
Display Decoded Text
print
print
"Decoded Cipher Text:", str3
print
main()