use python3

For the purpose of this lab exercise, write a program that implements a simple calculator that performs 2 steps: 1) converts an infix expression to a postfix expression, and 2) evaluates the postfix expression and finally prints out the result. You should use stack operations in both steps above. Your implementation can assume the following: The calculator handles only +,-, *, , , % operators * A single infix expression may have multiple operands, operators, and brackets . All operands are numerical values * All operands are a single digit each Tokens in the infix expression may or not be separated with white spaces All input infix expressions will be correct Your program will read a sequence of infix expressions from a text file, and may output the results either to the console or to an output file