code: def get_minimum_indentation(text):
      r
      lines = text.split('\n')
      indentations = [get_indentation(line_)
                      for line_ in lines  if len(line_.strip()) > 0]
      if len(indentations) == 0:
          return 0
      return min(indentations)
docs: r"""
      returns the number of preceding spaces
  
      Args:
          text (str): unicode text
  
      Returns:
          int: indentation
  
      CommandLine:
          python -m utool.util_str --exec-get_minimum_indentation --show
  
      Example:
          >>> # ENABLE_DOCTEST
          >>> from utool.util_str import *  # NOQA
          >>> import utool as ut
          >>> text = '    foo\n   bar'
          >>> result = get_minimum_indentation(text)
          >>> print(result)
          3