Python: loop and edit string character-CodePudding

I'm new to python and coding in general. Here is a problem from my homework, as well as my current code. I know that I only have one of the parts, but I wanted to figure this one out before moving on to the rest. With my loop, I can find and identify the letter i, but I can't figure out how to change the i's to 1's.

Problem:

Many user-created passwords are simple and easy to guess. Write a program that takes a simple password and makes it stronger by replacing characters using the key below, and by appending "!" to the end of the input string.
i becomes 1
a becomes @
m becomes M
B becomes 8
s becomes $
Ex: If the input is:
mypassword
the output is:
Myp@$$word!
Hint: Python strings are immutable, but support string concatenation. Store and build the stronger password in the given password variable.

Code:

word = input()
password = ()


for letter in word:
    if letter == 'i':
        password = password '1'
    else: password = password letter

print(password)

input: igigigig output: igigigig

CodePudding user response：

First off, you're initializing your password to an incorrect variable choice. password = () sets password to a tuple. Attempting to add characters to a tuple variable will lead to an exception:

>>> password = ()
>>> password = password   '1'
Traceback (most recent call last):
  File "<input>", line 1, in <module>
TypeError: can only concatenate tuple (not "str") to tuple

Next, you have a mapping of characters provided in the question. You can start by creating a dictionary to represent this mapping.

mapping = {
    'i': '1',
    'a': '@',
    'm': 'M',
    'B': '8',
    's': '$',
}

When looping against letters you can use the mapping to determine if a replacement should be made:

for letter in word:
    if letter in mapping:
        password = password   mapping.get(letter)
    else:
        password = password   letter

You also forgot to add the ! to the end.

Final result:

mapping = {
    'i': '1',
    'a': '@',
    'm': 'M',
    'B': '8',
    's': '$',
}

word = "mypassword"
password = ""

for letter in word:
    if letter in mapping:
        password = password   mapping[letter]
    else:
        password = password   letter
password  = "!"

print(password)

Simplifying this further:

for letter in word:
    password  = mapping.get(letter, letter)
password  = "!"

Even further with a comprehension!:

password = ''.join(mapping.get(l, l) for l in word)   "!"

CodePudding user response：

you can flow the step below

1.Change str(word) to list off str(letter)
2.Use loop check and change str(letter) in list one by one
3.Merge list off str(letter) to str(word)

Code :

word = list(word)

for position in range(len(word)):
    letter = word[position]
    if letter == 'i':
        word[position] = '1'

''.join(word)

CodePudding user response：

with the help of some of these comments and re-reading the instructions, I was able to find the right answer that the book was looking for.

word = input()
password=''


for letter in word:
    if letter == 'i':
        str1 = '1'
        password = password str1
    else: password = password letter

print(password)