input: Write a function to remove all punctuations from a given string of sentences. If the input string is empty, the function should return an empty string. Finally, if there are any numbers within the string, they should be preserved.
  
  assert remove_punctuations("This is a sample string!")=="This is a sample string"
  assert remove_punctuations("Another example, with a comma!")=="Another example with a comma"
  assert remove_punctuations("Empty input: ")==""
  assert remove_punctuations("Special characters (#@) and numbers like 123.")=="Special characters  and numbers like 123"
  assert remove_punctuations("")==""
output: def remove_punctuations(s):
      import string
      return ''.join(char for char in s if char not in string.punctuation)