1000 digits of pi in Python

I have been thinking about this issue and I can't figure it out. Perhaps you can assist me. The problem is my code isn't working to output 1000 digits of pi in the Python coding language.

Here's my code:

def make_pi():
    q, r, t, k, m, x = 1, 0, 1, 1, 3, 3
    while True:
        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 range(1000):
    my_array.append(str("hello, I'm an element in an array \n" ))
big_string = "".join(my_array)

print "here is a big string:\n %s" % big_string 

I know this code can be fixed to work, but I'm not sure what to fix... The print statement saying here is a big string and the my_array.append(str("hello, im an element in an array \n)) is just a filler for now. I know how all the code is used to work, but like I said before, I can't get it to shoot out that code.

Solution 1:

If you don't want to implement your own algorithm, you can use mpmath.

try:
    # import version included with old SymPy
    from sympy.mpmath import mp
except ImportError:
    # import newer version
    from mpmath import mp

mp.dps = 1000  # set number of digits
print(mp.pi)   # print pi to a thousand places

Reference

Update: Code supports older and newer installations of SymPy (see comment).*

Solution 2:

Run this

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


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 big string:\n %s" % big_string 

And read about yield operator from here: What does the "yield" keyword do?

Here is the answer:

3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679821480865132823066470938446095505822317253594081284811174502841027019385211055596446229489549303819644288109756659334461284756482337