Fenwick Tree with range update and query sum

class Ftree:
    def __init__(self, n):
        self.n = n
        self.tree1 = (n+1)*[0]
        self.tree2 = (n+1)*[0]
    def query(self, tree, r):
        s = 0
        while r > 0:
            s += tree[r]
            r -= r & -r
        return s
    def sum(self, r):
        return self.query(self.tree1, r)*r - self.query(self.tree2, r)
    def sum_range(self, l, r):
        return self.sum(r) - self.sum(l-1)
    def add(self, tree, k, x):
        while k <= self.n:
            tree[k] += x
            k += k & -k
    def add_range(self, l, r, x):
        self.add(self.tree1, l, x)
        self.add(self.tree1, r+1, -x)
        self.add(self.tree2, l, x*(l-1))
        self.add(self.tree2, r+1, -x *r)
# Initial array
a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
# Fenwick Tree
t = Ftree(10)
for i in range(10):
    # Adding data to tree
    t.add_range(i+1, i+1, a[i])
# Query range sum
print(t.sum_range(5, 9)) # 35
# Adding value to range
t.add_range(5, 9, 2)

print(t.sum_range(5, 9)) # 45
t.add_range(5, 6, 1)
print(t.sum_range(5, 9)) # 47