input: from typing import List
  
  def remove_punctuations(sentences: str) -> str:
      """ Remove all punctuations from a given string of sentences.
      >>> remove_punctuations("This is a sample string!")
      'This is a sample string'
      >>> remove_punctuations("Hello, World! How are you?")
      'Hello World How are you'
      """
output:     import string
      return ''.join([char for char in sentences if char not in string.punctuation])