for i in range(1, len(numbers_arr), 2):

if len(numbers_arr[i]) > 1:

if numbers_arr[i][0] == '-':

if len(numbers_arr[i]) % 2 != 0:

numbers_arr[i] = '-'

else:

numbers_arr[i] = '+'

else:

numbers_arr[i] = '+'

input_arr = user_input.split(' ')

for i, el in enumerate(input_arr):

if el[0] == '+':

input_arr[i] = el[1:]

if user_input[0] == '/' and (user_input != '/help' and user_input != '/exit'):

print('Unknown command')

return False

input_arr = convery_to_array_2(user_input)

op = ['^', '+', '-', '*', '/']

count_p_l = 0

count_p_r = 0

for i, el in enumerate(input_arr):

if i < len(input_arr)-1:

if el in op and input_arr[i+1] in op and ((el != '+' and input_arr[i+1] != '+') or(el != '-' and input_arr[i+1] != '-')):

print('Invalid expression')

return False

elif el == '(' and input_arr[i+1] == ')':

print('Invalid expression')

return False

elif el == ')' and input_arr[i+1] == '(':

print('Invalid expression')

return False

elif input_arr[len(input_arr) -1] in op:

print('Invalid expression')

return False

if el == '(':

count_p_l += 1

elif el == ')':

count_p_r += 1

if count_p_l != count_p_r:

print('Invalid expression')

return False

pattern_num = '[0-9]+'

pattern_letter = '[A-Za-z]+'

output = True

if '=' in user_input:

return True

for count, el in enumerate(input_arr):

if re.match(pattern_num, el):

if el[len(el) - 1] == '+' or el[len(el) - 1] == '-':

output = False

return output

elif re.match(pattern_num, el):

if count < len(input_arr) - 1 and re.match(pattern_num, input_arr[count + 1]):

output = False

return output

input_arr = re.split('\s+', user_input)

for i, el in enumerate(input_arr):

if len(el) > 1:

input_arr[i] = list(el)

equal_sign = 0

if '=' in input_arr:

for el in input_arr:

if el == '=':

equal_sign += 1

if equal_sign > 1:

print('Invalid assignment')

return False

if equal_sign == 1:

equal_s_index = input_arr.index('=')

first_part = ''.join(input_arr[:equal_s_index])

last_part = ''.join(input_arr[equal_s_index + 1:])

variable = ''.join(first_part)

if re.match('^[a-zA-Z]+$', variable):

if re.match('^[0-9]+$', ''.join(last_part)):

value = int(''.join(last_part))

variables[variable] = value

elif re.match('^[a-zA-Z]+$', ''.join(last_part)):

key = ''.join(last_part)

if key in variables:

variables[variable] = variables[key]

else:

print('Unknown variable')

return False

elif re.match('^[a-zA-Z0-9]+$', ''.join(last_part)):

print('Invalid assignment')

return False

elif re.match('^[a-zA-Z0-9]+$', ''.join(first_part)):

print('Invalid identifier')

if user_input in variables:

print(variables[user_input])

else:

for i, el in enumerate(input_arr):

if el in variables:

input_arr[i] = int(variables[el])

elif not el.isdigit() and el not in ['^', '+', '-', '*', '/', '(', ')']:

print('Unknown variable')

break

op = ['^', '+', '-', '*', '/', '(', ')']

index = 0

res = []

for i in range(len(str)):

if str[i] in op:

res.append(str[index: i])

res.append(str[i])

index = i + 1

res.append(str[index:len(str)])

res = [x.strip() for x in res if x.strip() != '']

prec = {}

prec["*"] = 3

prec["/"] = 3

prec["+"] = 2

prec["-"] = 2

prec["("] = 1

opStack = Stack()

postfixList = []

tokenList = infixexpr_arr

for token in tokenList:

token = token.strip() # '33 ' -> '33'

if re.match('^[a-zA-Z]+$', token) or re.match('^[0-9]+$', token):

postfixList.append(token)

elif re.match('^[a-zA-Z0-9]+$', token): # 'a22'

print('Invalid identifier')

break

elif token == '(':

opStack.push(token)

elif token == ')':

topToken = opStack.pop()

while topToken != '(':

postfixList.append(topToken)

topToken = opStack.pop()

else:

while (not opStack.isEmpty()) and (prec[opStack.peek()] >= prec[token]):

postfixList.append(opStack.pop())

opStack.push(token)

while not opStack.isEmpty():

postfixList.append(opStack.pop())

op = ['^', '+', '-', '*', '/']

equation = deque()

for el in postfix:

equation.append(el)

for i, el in enumerate(equation):

if el not in op:

equation[i] = int(el)

que_helper = deque()

result = 0

if len(equation) == 1:

result = equation.pop()

else:

while len(equation) > 0:

x = equation.popleft()

if x not in op:

que_helper.appendleft(x)

else:

b = que_helper.popleft()

a = que_helper.popleft()

if x == '^':

result = a ** b

elif x == '*':

result = a * b

elif x == '/':

result = a / b

elif x == '+':

result = a + b

elif x == '-':

result = a - b

que_helper.appendleft(result)

print(int(result))