parameters: (self, fail_value=-1)
docstring: Get a number from the packet. The number must be in big endian format and should be parsed
          according to its prefix (starts with "0x" means hex, starts with "0" means octal, starts with
          [1-9] means decimal, etc)
docstring_summary: Get a number from the packet. The number must be in big endian format and should be parsed
          according to its prefix (starts with "0x" means hex, starts with "0" means octal, starts with
          [1-9] means decimal, etc)
docstring_tokens: Get a number from the packet . The number must be in big endian format and should be parsed according to its prefix ( starts with 0x means hex starts with 0 means octal starts with [ 1 - 9 ] means decimal etc )
function: def get_number(self, fail_value=-1):
          '''Get a number from the packet. The number must be in big endian format and should be parsed
          according to its prefix (starts with "0x" means hex, starts with "0" means octal, starts with
          [1-9] means decimal, etc)'''
          match = g_number_regex.match(self.str)
          if match:
              number_str = match.group(1)
              self.str = self.str[len(number_str):]
              return int(number_str, 0)
          else:
              return fail_value
function_tokens: def get_number ( self , fail_value = - 1 ) : match = g_number_regex . match ( self . str ) if match : number_str = match . group ( 1 ) self . str = self . str [ len ( number_str ) : ] return int ( number_str , 0 ) else : return fail_value