Buggy python submission (verdict: Time Limit Exceeded):
import sys
import math
from collections import defaultdict

sys.setrecursionlimit(10**7)
def input():
    return sys.stdin.readline()[:-1]

mod = 10**9 + 7

def I(): return int(input())
def LI(): return list(map(int, input().split()))
def MI(N,num):
    if N<=0:
        return [[] for _ in range(num)]
    elif num==1:
        return [I() for _ in range(N)]
    else:
        read_all = [LI() for _ in range(N)]
        return map(list, zip(*read_all))

#################

#0!~(n-1)!をmodしつつ求める
def fact_all(n,M=mod):
    f = [1]*n
    ans = 1
    for i in range(1,n):
        ans = (ans*i)%M
        f[i] = ans
    return f


#a!をmodしつつ求める
def fact(a,M=mod):
    ans = 1
    for i in range(2,a+1):
        ans = (ans*i)%M
    return ans


#互いに素なa,bについて、a*x+b*y=1の一つの解[x,y]を出力
def extgcd(a,b):
    r = [1,0,a]
    w = [0,1,b]
    while w[2]!=1:
        q = r[2]//w[2]
        r2 = w
        w2 = [r[0]-q*w[0],r[1]-q*w[1],r[2]-q*w[2]]
        r = r2
        w = w2
    return [w[0],w[1]]


#aの逆元(mod M)を求める（aとMは互いに素）
def mod_inv(a,M=mod):
    x = extgcd(a,M)[0]
    return (M+x%M)%M


#nCkをmodしつつ返す
def nCk(n,k,fact_list=[],inv_list=[],M=mod):
    if fact_list and inv_list:
        return (fact_list[n]*inv_list[k]*inv_list[n-k])%M
    else:
        x = fact(n,M)
        y1 = mod_inv(fact(k,M),M)
        y2 = mod_inv(fact(n-k,M),M)
        return (x*y1*y2)%M


def g(r,c):
    retval = 0
    for i in range(r+1):
        retval += nCk(i+c+1,c,fact_list,inv_list)
        retval %= mod
    return retval

r1,c1,r2,c2 = LI()
fact_list = fact_all(r2+c2+2)
inv_list = [mod_inv(f) for f in fact_list]

print((g(r2,c2)-g(r2,c1-1)-g(r1-1,c2)+g(r1-1,c1-1))%mod)

Fixed submission:
import sys
import math
from collections import defaultdict

sys.setrecursionlimit(10**7)
def input():
    return sys.stdin.readline()[:-1]

mod = 10**9 + 7

def I(): return int(input())
def LI(): return list(map(int, input().split()))
def MI(N,num):
    if N<=0:
        return [[] for _ in range(num)]
    elif num==1:
        return [I() for _ in range(N)]
    else:
        read_all = [LI() for _ in range(N)]
        return map(list, zip(*read_all))

#################

#0!~(n-1)!をmodしつつ求める
def fact_all(n,M=mod):
    f = [1]*n
    ans = 1
    for i in range(1,n):
        ans = (ans*i)%M
        f[i] = ans
    return f


#a!をmodしつつ求める
def fact(a,M=mod):
    ans = 1
    for i in range(2,a+1):
        ans = (ans*i)%M
    return ans


#互いに素なa,bについて、a*x+b*y=1の一つの解[x,y]を出力
def extgcd(a,b):
    r = [1,0,a]
    w = [0,1,b]
    while w[2]!=1:
        q = r[2]//w[2]
        r2 = w
        w2 = [r[0]-q*w[0],r[1]-q*w[1],r[2]-q*w[2]]
        r = r2
        w = w2
    return [w[0],w[1]]


#aの逆元(mod M)を求める（aとMは互いに素）
def mod_inv(a,M=mod):
    x = extgcd(a,M)[0]
    return (M+x%M)%M


#nCkをmodしつつ返す
def nCk(n,k,fact_list=[],inv_list=[],M=mod):
    if fact_list and inv_list:
        return (((fact_list[n]*inv_list[k])%M)*inv_list[n-k])%M
    else:
        x = fact(n,M)
        y1 = mod_inv(fact(k,M),M)
        y2 = mod_inv(fact(n-k,M),M)
        return (x*y1*y2)%M


def g(r,c):
    retval = 0
    for i in range(r+1):
        retval += nCk(i+c+1,c,fact_list,inv_list)
        retval %= mod
    return retval

r1,c1,r2,c2 = LI()
fact_list = fact_all(r2+c2+2)
inv_list = [mod_inv(f) for f in fact_list]

print((g(r2,c2)-g(r2,c1-1)-g(r1-1,c2)+g(r1-1,c1-1))%mod)