input: Write a function to remove all punctuations from a given string of sentences. If the given string is empty then return an empty string.
  assert remove_punctuations("This is a sample string!") == "This is a sample string"
  assert remove_punctuations("Hello, World!") == "Hello World"
  assert remove_punctuations("!@#$%^&*()") == ""
  assert remove_punctuations("") == ""
output: def remove_punctuations(s):
      import string
      return ''.join(char for char in s if char not in string.punctuation)