str[n]= "" for deleting string characters

Question

Why this doesn't work for removing characters from strings in python?

  return str[n]= ""

and we are forced to use this:

  front = str[:n]   # up to but not including n
  back = str[n+1:]  # n+1 through end of string
  return front + back

The Problem: Given a non-empty string and an int n, return a new string where the char at index n has been removed. The value of n will be a valid index of a char in the original string (i.e. n will be in the range 0..len(str)-1 inclusive).

missing_char('kitten', 1) → 'ktten'
missing_char('kitten', 0) → 'itten'
missing_char('kitten', 4) → 'kittn'

enter image description here

Because [strings are immutable](https://stackoverflow.com/a/986145/843953) — Pranav Hosangadi, Sep 16 '20 at 21:49
Also the pattern `return sequence[n] = ""` raises a `SyntaxError` — jkr, Sep 16 '20 at 21:53
Even if it were possible in Python, from the homework assignment: "return a *new* string..." (emphasis mine). Not the same string with characters deleted. — Jared Smith, Sep 16 '20 at 21:53

score 1 · Accepted Answer · answered Sep 16 '20 at 22:04

1

one way of doing it is by iterating over all letters with the index via the enumerate method:

def remove_index_from(example_string):
    return "".join([letter for index,letter in enumerate(example_string) if index != index_to_remove])

answered Sep 16 '20 at 22:04

lhd

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str[n]= "" for deleting string characters

1 Answers1