# hello.py3  example file  indetation and blank lines important
#           simple .py can be without  def main():  
#                                      if __name__ == '__main__':
#                                      main()
import math

def main():
  print("hello from python")  # three ways to print the same line
  print('hello from python')
  print("hello","from python")
  a_int=7
  a_float=7.25
  a_real=7.2597256357e+300
  print("a_int=",a_int)
  print("a_float=",a_float)
  print("a_real=",a_real)

  a_list=[7, 7.25, "abc"]
  print("a_list=",a_list)
  print("a_list[2]=",a_list[2])
  a_list.append("def")
  print("append=", a_list)
  del a_list[1]
  print("delete=", a_list)
  print("len(a_list)=",len(a_list))
  print(" ")

  a_tuple=2, 3, 5, 7   # can not modify
  b_tuple=(2, 3, 5, 7) # same as above
  print("a_tuple=",a_tuple)
  print("b_tuple=",b_tuple)
  print("b_tuple[2]=",b_tuple[2])
  print(" ")

  dict={1:'a', 2:'b', 3:'c'} # dictionary key : value
  print("dict=",dict)
  dict[5]='e'
  print("dict 5=",dict)
  print("dict[3]=",dict[3]) # look up by key
  print(" ")

  z=range(5)
  print("range(5)=",z)
  z=range(1,5)
  print("range(1,5)=",z)
  z=range(1,7,2)
  print("range(1,7,2)=",z)

  x = 0.7071
  print("x = ",x)
  print("anyfunct(x) =",anyfunct(x)) #   note complex result",

# end of main

def anyfunct(x): # thus main can be in front of needed funstions, cmath also
  z = math.cos(x) + 1.0j*math.sin(x) - math.sqrt(x)
  return z


if __name__ == '__main__':
  main()

# end of hello.py3 see also  test_math.py3