pi

import numpy
import scipy
import math
import sympy
from decimal import *

print(math.pi)
print(numpy.pi)
print(scipy.pi)
print(sympy.pi)
r = 5
print(math.pi*(r**2))
print(numpy.pi*(r**2))
print(scipy.pi*(r**2))
print(sympy.pi*(r**2))


def make_pi():
    q, r, t, k, m, x = 1, 0, 1, 1, 3, 3
    for j in range(1000):
        if 4 * q + r - t < m * t:
            yield m
            q, r, t, k, m, x = 10*q, 10*(r-m*t), t, k, (10*(3*q+r))//t - 10*m, x
        else:
            q, r, t, k, m, x = q*k, (2*q+r)*x, t*x, k+1, (q*(7*k+2)+r*x)//(t*x), x+2


digits = make_pi()
pi_list = []
my_array = []

for i in make_pi():
    my_array.append(str(i))

my_array = my_array[:1] + ['.'] + my_array[1:]
big_string = "".join(my_array)
print "here is a pi as a string:\n %s" % big_string
pi = Decimal(big_string)
print("pi is %s" %(Decimal(big_string)))
r = Decimal(5.0000000000000000000000000000000000000000000)
print("now we can do math with pi")
print(Decimal(Decimal(pi)*r**2))