def translate(phrase):
    translation = ""
    for letter in phrase:
        if letter in " ":
            translation = translation + "@"
result = (input("enter a phrase you want encrypted: "))
result = translate(result)

Traceback (most recent call last):
  File "D:helloencrydecryencryption1.py", line 158, in <module
>
    result = (input("enter a phrase you want encrypted: "))
  File "<string>", line 1, in <module>
NameError: name 'hello' is not defined

result = raw_input("enter a phrase you want encrypted: ")

def translate(phrase):
    translation = ""
    for letter in phrase:
        if letter in " ":
            translation = translation + "@"
result =raw_input("enter a phrase you want encrypted: ")
result = translate(result)