""" From "COMPUTATIONAL PHYSICS" & "COMPUTER PROBLEMS in PHYSICS"
    by RH Landau, MJ Paez, and CC Bordeianu (deceased)
    Copyright R Landau, Oregon State Unv, MJ Paez, Univ Antioquia, 
    C Bordeianu, Univ Bucharest, 2017. 
    Please respect copyright & acknowledge our work."""
	 
# Directives.py illustrates escape and formatting  characters
import sys
print("hello \n")
print("\t it's me")                         # tabulator
b = 73
print("decimal 73 as integer b = %d "%(b))  # for integer
print("as octal b = %o"%(b))                # octal
print("as hexadecimal b = %x "%(b))         # works hexadecimal
print("learn \"Python\" ")                  # use of double quote symbol
print("shows a backslash \\")               # use of \\
print('use of single \' quotes \' ')        # print single quotes