Hi there,

I am completely new to Python and have taken over a class midway through their course. I am myself learning using the Computer Science Circles Course but i have run into a problem that I can’t help a student with at my level of experience. I know in principle what the problem is but I am having difficulty crafting a solution.

Problem is read a file, working, encrypt the file, save and generate an 8 character key working, enter key and decrypt the new file not working. The file uses an offset to encrypt to ASCII characters.

Code below:

try:

print(“Welcome to encryption”)

print(“Please Select an operation”)

print(“1. Encryption”)

print(“2. Decryption”)

print(“3. Terminate Program”)

#users Choice of operation

choice = input("ENTER YOUR CHOICE (1/2/3): ")

```
def encrypt():
file = input("enter you file name: ")
print("Key:")
keytotal = 0
key = []
OF = 0
for v in range(0,8):
num = random.randint(33,126)
keytotal = keytotal + num
key.append(chr(num))
print(key[v],end="")
fo = open(file,"r+")
fo = fo.read()
print(" ")
#offset factor
OF = math.floor(keytotal/8)-32
print("Offset Factor:")
print(OF)
s = [ord(i) + OF for i in fo]
for length in range(0, len(s)):
if s[length] == 32 + OF:
s[length] = s[length] - OF
elif s[length] > 125:
s[length] = s[length] - 94
encrypted = [chr(i) for i in s]
final = ''.join(encrypted)
FF = input("What Would You Like To Save Your Encription As?: ")
nf = open(FF,"a+")
nf.writelines(final)
nf.close()
def decrypt():
file = input("enter you file name: ")
fo = open(file,"r+")
fo = fo.read()
print(" ")
OF = 0
key = []
s = 0
#finding the offset factor
key = input("enter your 8 digit key: ")
for x in key:
OF=OF+ord(x)
OF = (math.floor(OF*8)+32)
s = [ord(i) + OF for i in fo]
for length in range(0, len(s)):
if s[length] == 32 - OF:
s[length] = s[length] + OF
elif s[length] > 32:
s[length] = s[length] + 94
encrypted = [chr(i) for i in s]
final = ''.join(encrypted)
FF = input("What Would You Like To Save Your Encryption As?: ")
nf = open(FF,"a+")
nf.writelines(final)
nf.close()
if choice == "1":
encrypt()
elif choice == "2":
decrypt()
elif choice == "3":
exit()
```

#except ValueError:

#print(“try again”)