import math
# 1. Complex arithmetic
# 2. Conditionals
# 3. Lists
# 4. tuples

def sep() :
	sepstring = ""
	sepstring += "  "
	for i in range(75) :
		sepstring += "-"
	sepstring += "  "
	print sepstring

def header(s) :
	print " "
	sep()
	print "          " + s
	sep()
	print " "

# One more arithmetic operator : %
# As some of you have observed for numbers n and d the quotient and
# the remainder are given by
header("Integer division")
n = input("divident : ")
d = input("divisor : ")
print "Quotient = %d, remainder = %d." % (n/d, n%d)

# 1. Complex arithmetic
header("Complex aritmetic")

u = 1 + 1j
v = 0.70710678 + 0.70710678j
w = math.sqrt(1.0/2) + math.sqrt(1.0/2) * 1j
u2 = u * u
v2 = v * v
w2 = w ** 2
print "u^2 = %g + %gj; v^2 = %g + %gj and w^2 = %g + %gj" % (u2.real, \
	u2.imag, v2.real, v2.imag, w2.real, w2.imag) # introducing line break.

# This does not work
# print math.sqrt(-1)
# However this works
import cmath
print "Square root of -1 is %g + %gj" % (cmath.sqrt(-1).real, cmath.sqrt(-1).imag)

#ipython and timing commands.

# 2. Conditionals
# let us use a conditional here.
n = input("Find the square root of the complex number : ")
n = complex(n)
if n.imag == 0 :
	if n.real >= 0 :
		root_real = math.sqrt(n.real)
		root_imag = 0
	else :
		root_real = 0
		root_imag = math.sqrt(-n.real)
else :
	root = cmath.sqrt(n)
	root_real = root.real
	root_imag = root.imag

print "The root is %g + %g j" % (root_real, root_imag)

# else is always not necessary

f = input("To find the absolute value of the real no. : ")
if f < 0 :
    f = -f
print f


# 3. Lists
header("Lists")
# We encountered lists when we saw the range function.
print "range(10) = "
print range(10)
print "range(3, 10) = "
print range(3, 10)
print "range(-5) = "
print range(-5)

mylist = ["Bread", 0, 1, math.e]
print mylist
print "mylist[2] = %g" % (mylist[2])
mylist.append("new element")
print "After appending \'new element\': ",
print mylist

mylist.insert(1,42)
print "Inserting the answer to the qn on Life, Universe and Everything at \
position 1 : "
print mylist
print "Deleting entry 2"
del mylist[2]
print mylist

newlist = ["some", 2, "more", 54, "elements"]
print "newlist : ",
print newlist
mylist = mylist + newlist
print "appending new list to mylist : ",
print mylist

print "mylist entries from 2 - 4 : ",
print mylist[2:5]
print "mylist entries from 2 onwards : " + str(mylist[2:])
print "mylist entries upto 5 : " + str(mylist[:6])