input: Write a function to remove all punctuations from a given string of sentences. If the input string is empty return it as is. Use Python's string module to handle punctuations.
  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("Python programming is fun!")=="Python programming is fun"
  assert remove_punctuations("Testing: 1, 2, 3.")=="Testing 1 2 3"
output: def remove_punctuations(s):
      import string
      if not s:
          return s
      return ''.join(char for char in s if char not in string.punctuation)