<human>:  What is a good Python function to remove characters from strings except for the characters that are not in the string.
<bot>: Here is a Python function to remove characters from strings except for the characters that are not characters

import string

def remove_except(string, chars):
  """
  >>> remove_except("abcdefg", "a")
  'bcdefg'
  """
  return ''.join(c for c in string if c not in chars)

# Enter the string
string ="red airplane"

# Calling the function
string_without_chars = remove_except(string, "a")

# Print the string
print(string_without_chars)

#Example Output

# red irplne

#Remember to inspect code for bugs.