print "Hello World!" print 2 + 2 2 + 2 print 2.1 + 2 2.1 + 2 == 4.0999999999999996 2L 2L + 2 2L/2 2L/2.0 complex(1,2) 1+2j 1 + 2j - 2j (3.0*10.0 - 25.0)/5.0 print 3.085e18*1e6 # this is a Megaparsec in units of cm! t = 1.0 # declare a variable t (time) accel = 9.8 # acceleration in units of m/s^2 # distance travelled in time t seconds is 1/2 a*t**2 dist = 0.5*accel*t*t print dist # this is the distance in meters dist1 = accel*(t**2)/2 print dist1 dist2 = 0.5*accel*pow(t,2) print dist2 print 6 / 5 ; print 9 / 5 # integer division returns the floor 6 % 5 # mod operator 1 << 2 ## shift: move the number 1 by two bits to the left ## that is make a new number 100 (base 2) 5 >> 1 ## shift: move the number 5 = 101 (base 2) one to ## to the right (10 = 2) x = 2 ; y = 3 ## assign two variables on the same line! x | y ## bitwise OR x ^ y ## exclusive OR (10 ^ 11 = 01) x & y ## bitwise AND x = x ^ y ; print x x += 3 ; print x x /= 2.0 print x dist1 = 4.9 ; dist = 4.9 dist1 == dist dist < 10 dist <= 4.9 dist < (10 + 2j) dist < -2.0 dist != 3.1415 # in the future you could use math.pi 0 == False not False 0.0 == False not (10.0 - 10.0) not -1 not 3.1415 x = None # None is something special. Not true or false print None == False print None == True print None == None print False or True print False and True print type(1) x = 2 ; print type(x) type(2) == type(1) print type(True) print type(type(1)) print type(pow) print isinstance(1,int) print isinstance("spam",str) print isinstance(1.212,int) x = "spam" ; type(x) print "hello!\n...my sire." "hello!\n...my sire." "wah?!" == 'wah?!' print "'wah?!' said the student" print "\"wah?!\" said the student" # raw strings don't escape characters print r'This is a raw string...newlines \r\n are ignored.' # Triple quotes are real useful for multiple line strings y = '''For score and seven minutes ago, you folks all learned some basic mathy stuff with Python and boy were you blown away!''' print y s = "spam" ; e = "eggs" print s + e print s + " and " + e print "green " + e + " and\n " + s print s*3 + e print "*"*50 print "spam" is "good" ; print "spam" is "spam" "spam" < "zoo" "s" < "spam" print 'I want' + 3 + ' eggs and no ' + s print 'I want ' + str(3) + ' eggs and no ' + s pi = 3.14159 print 'I want ' + str(pi) + ' eggs and no ' + s print str(True) + ":" + ' I want ' + str(pi) + ' eggs and no ' + s s = 'spam' len(s) len("eggs\n") len("") print s[0] print s[-1] x = 1 if x > 0: print "yo" else: print "dude" x = 1 if x > 0: print "yo" else: print "dude" print "yo" if x > 0 else "dude" if x < 1: print "t" elif x > 100: print "yo" else: print "dude" x = "fried goldfish" if x == "spam for dinner": print "I will destroy the universe" else: # I'm fine with that. I'll do nothing x = "fried goldfish" if x == "spam for dinner": print "I will destroy the universe" else: # I'm fine with that. I'll do nothing pass