import Calc

failure = True
while (failure == True):
        string = input()

        n = ""
        nums = []
        operators = []

        for c in string:
                if (c >= '0' and c <= '9'):
                        n += c
                else:
                    if (n != ""):
                        nums.append(float(n))
                        n = ""
        if (n != ""):
                nums.append(float(n))

        for b in string:
                if (b == "+" or b == "*" or b =="/" or b == "^"
                    or b == "-" or b == "(" or b == ")"): 
                         operators.append(b)

        test_ops = []
        for op in operators:
            if (op != "(" and op != "("):
                test_ops.append(op)
    
        if len(test_ops)>len(nums):
            print ("Error! Please try again.")
        elif len(nums)-1>len(operators):
            print ("Error! Please try again.")
        else:
            failure = False
            print(Calc.calc(nums, operators))
input("Press Enter To Continue: ")

def get_result(nums, ops):
    while(ops != []):
        opn = -1
        n = 0
        while (n < len(ops)):
            if (opn == -1):
                    opn = n
            else:
                if (ops[opn] == '+' or ops[opn] == '-'):
                    if (ops[n] == '*' or ops[n] == '/'):
                        opn = n
                if (ops[opn] == '*' or ops[opn] == '/' or ops[opn] == '+' or ops[opn] == '-'):
                    if (ops[n] == '^'):
                        opn = n
            n+=1
        if (ops[opn] == '+'):
            nums.insert(opn, nums.pop(opn) + nums.pop(opn))
        elif (ops[opn] == '-'):
            nums.insert(opn, nums.pop(opn) - nums.pop(opn))
        elif (ops[opn] == '*'):
            nums.insert(opn, nums.pop(opn) * nums.pop(opn))
        elif (ops[opn] == '/'):
            nums.insert(opn, nums.pop(opn) / nums.pop(opn))
        elif (ops[opn] == '^'):
            nums.insert(opn, nums.pop(opn) ** nums.pop(opn))
        ops.pop(opn)
    return nums[0]


def calc(nums, ops):
    mod_ops = []
    brackets = []
    
    for i in range(len(ops)):
        if (ops[i] != '(' and ops[i] != ')'):
            mod_ops += ops[i]
        else:
            if ops[i] != ')':
                temp = "open"
            else:
                temp = "close"
            brackets.append([len(mod_ops), temp])

    while (len(brackets)>0):
        index = -1
        for i in range(len(brackets)):
            if (brackets[i][1] == "open"):
                index = i
        if (index != -1):
            ob = brackets.pop(index)
            cb = brackets.pop(index)
            new_ops = mod_ops[ob[0]:cb[0]]
            mod_ops[ob[0]:cb[0]] = []
            new_nums = nums[ob[0]:cb[0]+1]
            nums[ob[0]:cb[0]+1] = [get_result(new_nums, new_ops)]
        else:
            break
    return get_result(nums, mod_ops)

10 + 5 * x = 20

[10,5,x,20]

['+', '*', '=']

"10 * 2+ 3= "

import Calc

failure = True

while (failure == True):

string = input()

"10 * 2+ 3= "

        n = ""

        nums = []
        operators = []

        for c in string:

                if (c >= '0' and c <= '9'):

n += c

else:
                    if (n != ""):

nums.append(float(n))
                        n = ""

if (n != ""):
                nums.append(float(n))

"10 * 2+ 3= "

for c in string:

if (c >= '0' and c <= '9'):
                        n += c

else:
                    if (n != ""):
                        nums.append(float(n))
                        n = ""

[10]

  if (n != ""):

[10, 2]

[10, 2, 3]

1 + 2 * 3

        for b in string:
                if (b == "+" or b == "*" or b =="/" or b == "^"
                    or b == "-" or b == "(" or b == ")"): 
                         operators.append(b)

10 * 2 + 3

test_ops = []
        for op in operators:
            if (op != "(" and op != "("):
                test_ops.append(op)
    
        if len(test_ops)>len(nums):
            print ("Error! Please try again.")
        elif len(nums)-1>len(operators):
            print ("Error! Please try again.")
        else:
            failure = False
            print(Calc.calc(nums, operators))

def calc(nums, ops):

mod_ops = []
    brackets = []

for i in range(len(ops)):
        if (ops[i] != '(' and ops[i] != ')'):
            mod_ops += ops[i]

else:
            if ops[i] != ')':
                temp = "open"
            else:
                temp = "close"
            brackets.append([len(mod_ops), temp])

len(mod_ops)

    while (len(brackets)>0):
        index = -1
        for i in range(len(brackets)):
            if (brackets[i][1] == "open"):
                index = i
        if (index != -1):
            ob = brackets.pop(index)
            cb = brackets.pop(index)
            new_ops = mod_ops[ob[0]:cb[0]]
            mod_ops[ob[0]:cb[0]] = []
            new_nums = nums[ob[0]:cb[0]+1]
            nums[ob[0]:cb[0]+1] = [get_result(new_nums, new_ops)]
        else:
            break
    return get_result(nums, mod_ops)

['*', '(', '*', '(', '+', ')', ')']

[2, 3, 1, 2]

2 * ( 3 * ( 1 + 2 ) )