Buggy python submission (verdict: Time Limit Exceeded):
import sys

sys.setrecursionlimit(10 ** 6)
int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def MI(): return map(int, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def SI(): return sys.stdin.readline()[:-1]

class mint:
    def __init__(self, x):
        self.__x = x % md

    def __str__(self):
        return str(self.__x)

    def __add__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x + other)

    def __sub__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x - other)

    def __rsub__(self, other):
        return mint(other - self.__x)

    def __mul__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x * other)

    __radd__ = __add__
    __rmul__ = __mul__

    def __truediv__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x * pow(other, md - 2, md))

    def __pow__(self, power, modulo=None):
        return mint(pow(self.__x, power, md))

def nCr(com_n, com_r):
    if com_n < com_r: return 0
    return fac[com_n] * ifac[com_r] * ifac[com_n - com_r]

def s(r, c):
    return nCr(r + c + 2, r + 1)

r1, c1, r2, c2 = MI()
md = 10**9+7
n_max = r2+c2+5
fac = [mint(1)]
for i in range(1, n_max + 1): fac.append(fac[-1] * i)
ifac = [1] * (n_max + 1)
ifac[n_max] = fac[n_max] ** (md - 2)
for i in range(n_max - 1, 1, -1): ifac[i] = ifac[i + 1] * (i + 1)

def main():
    ans=s(r2,c2)-s(r1-1,c2)-s(r2,c1-1)+s(r1-1,c1-1)
    print(ans)

main()

Fixed submission:
import sys

sys.setrecursionlimit(10 ** 6)
int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def MI(): return map(int, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def SI(): return sys.stdin.readline()[:-1]

class mint:
    def __init__(self, x):
        self.__x = x % md

    def __str__(self):
        return str(self.__x)

    def __add__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x + other)

    def __sub__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x - other)

    def __rsub__(self, other):
        return mint(other - self.__x)

    def __mul__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x * other)

    __radd__ = __add__
    __rmul__ = __mul__

    def __truediv__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x * pow(other, md - 2, md))

    def __pow__(self, power, modulo=None):
        return mint(pow(self.__x, power, md))

def nCr(com_n, com_r):
    if com_n < com_r: return 0
    return fac[com_n] * ifac[com_r] * ifac[com_n - com_r]

def s(r, c):
    return nCr(r + c + 2, r + 1)

r1, c1, r2, c2 = MI()
md = 10**9+7
n_max = r2+c2+5
fac = [mint(1)]
for i in range(1, n_max + 1): fac.append(fac[-1] * i)
ifac = [1] * (n_max + 1)
ifac[n_max] = fac[n_max] ** (md - 2)
for i in range(n_max - 1, 1, -1): ifac[i] = ifac[i + 1] * (i + 1)

def main():
    ans=s(r2,c2)-s(r1-1,c2)-s(r2,c1-1)+s(r1-1,c1-1)
    print(ans)

main()

Buggy python submission (verdict: Time Limit Exceeded):
import sys

sys.setrecursionlimit(10 ** 6)
int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def MI(): return map(int, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def SI(): return sys.stdin.readline()[:-1]

class mint:
    def __init__(self, x):
        self.__x = x % md

    def __str__(self):
        return str(self.__x)

    def __add__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x + other)

    def __sub__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x - other)

    def __rsub__(self, other):
        return mint(other - self.__x)

    def __mul__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x * other)

    __radd__ = __add__
    __rmul__ = __mul__

    def __truediv__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x * pow(other, md - 2, md))

    def __pow__(self, power, modulo=None):
        return mint(pow(self.__x, power, md))

def nCr(com_n, com_r):
    if com_n < com_r: return 0
    return fac[com_n] * ifac[com_r] * ifac[com_n - com_r]

md = 10**9+7
n_max = 10**6+5
fac = [mint(1)]
for i in range(1, n_max + 1): fac.append(fac[-1] * i)
ifac = [1] * (n_max + 1)
ifac[n_max] = fac[n_max] ** (md - 2)
for i in range(n_max - 1, 1, -1): ifac[i] = ifac[i + 1] * (i + 1)

def main():
    def s(r,c):
        return nCr(r+c+2,r+1)

    r1,c1,r2,c2=MI()
    ans=s(r2,c2)-s(r1-1,c2)-s(r2,c1-1)+s(r1-1,c1-1)
    print(ans)

main()

Fixed submission:
import sys

sys.setrecursionlimit(10 ** 6)
int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def MI(): return map(int, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def SI(): return sys.stdin.readline()[:-1]

class mint:
    def __init__(self, x):
        self.__x = x % md

    def __str__(self):
        return str(self.__x)

    def __add__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x + other)

    def __sub__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x - other)

    def __rsub__(self, other):
        return mint(other - self.__x)

    def __mul__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x * other)

    __radd__ = __add__
    __rmul__ = __mul__

    def __truediv__(self, other):
        if isinstance(other, mint): other = other.__x
        return mint(self.__x * pow(other, md - 2, md))

    def __pow__(self, power, modulo=None):
        return mint(pow(self.__x, power, md))

def nCr(com_n, com_r):
    if com_n < com_r: return 0
    return fac[com_n] * ifac[com_r] * ifac[com_n - com_r]

def s(r, c):
    return nCr(r + c + 2, r + 1)

r1, c1, r2, c2 = MI()
md = 10**9+7
n_max = r2+c2+5
fac = [mint(1)]
for i in range(1, n_max + 1): fac.append(fac[-1] * i)
ifac = [1] * (n_max + 1)
ifac[n_max] = fac[n_max] ** (md - 2)
for i in range(n_max - 1, 1, -1): ifac[i] = ifac[i + 1] * (i + 1)

def main():
    ans=s(r2,c2)-s(r1-1,c2)-s(r2,c1-1)+s(r1-1,c1-1)
    print(ans)

main()