CODEWITHSUNDEEP
pythonpython-3.x
user10980219
user10980219

Reputation:

Functions with AttributeError: 'NoneType' object has no attribute 'replace'

My mini program takes a string from user input and adds dots between each letter and then removes these dots.

The function add_dots takes the string and adds dots. I have a separate function called remove_dots that then removes them.

Here is the code below:

def add_dots(str):
  str = ".".join(str)
  print(str)

def remove_dots(str):
  str.replace(".", "")
  print(str)

word = input("Enter a word: ")

When I call the two functions individually with

add_dots(word)
remove_dots(word)

I get the expected console output of

Enter a word: hello
h.e.l.l.o
hello

However, when I try to call

remove_dots(add_dots(word))

I get an error AttributeError: 'NoneType' object has no attribute 'replace'

I understand that this means the str variable has the value of None but I'm not sure why? Can anyone advise. Thanks

Upvotes: 0

Views: 5174

Answers (4)

Arthur Minovsky
Arthur Minovsky

Reputation: 1

When you return in something in function, You have to convert return in other datatype such as list , string. In this case, Your first function it should be

def add_dots(string):
  string = ".".join(string)
  print(string)
  return str(string)

And second function should be

 def remove_dots(string):
    string = string.replace(".", "")
    print(string)
    return str(string)

Because anything that return from function, It return "Nonetype" as default. And Nonetype no method __getitem__

ref:https://www.pythonpool.com/typeerror-nonetype-object-is-not-subscriptable/

Upvotes: 0

Angelo
Angelo

Reputation: 94

def add_dots(str):
    str = ".".join(str)
    print(str)
    return str

def remove_dots(str):
    str = str.replace(".", "")
    print(str)
    return str

this should fix your code.

See @Chris and @Michael Butscher comments on your post

Upvotes: 0

Mitchell Olislagers
Mitchell Olislagers

Reputation: 1817

Your functions don't return anything. Also, the output of str.replace(".", "") is not stored. This should work.

def add_dots(str):
  return ".".join(str)

def remove_dots(str):
  return str.replace(".", "")

Upvotes: 0

Picachieu
Picachieu

Reputation: 3782

This is caused because your add_dots and remove_dots functions aren't actually returning anything, they're just printing values. Thus, passing the output of add_dots to remove_dots results in the value None being passed.

Also note that using str as a variable name is generally a bad idea; using string or a more descriptive name is better practice.

Change your code to return the modified strings, like so:

def add_dots(string):
  string = ".".join(string)
  return string

def remove_dots(string):
  string = string.replace(".", "")
  return string

word = input("Enter a word: ")

And print the outputs like so:

print(add_dots(word))
print(remove_dots(word))
print(remove_dots(add_dots(word)))

Upvotes: 2

Related Questions