Leibniz formula for pi

leibniz.py

from decimal import *
getcontext().prec = 15
t=[]
for i in range(int(raw_input())):
    t.append(raw_input())
for i in range(len(t)):
    o=t[i]
    l=[]
    for j in range(int(o)):
        p=Decimal((2*j) + 1)
        m=Decimal(1/p)
        if j%2 != 0:
            m=m*(-1)
        l.append(m)
    print sum(l)