Python creating a calculator

Question

I am fairly new to python.

I have been asked to create a calculator using only string commands, conversions between int/string/float etc.(if needed), and using funct

Answer 1

I have an alternative to your code. The user can enter stuff like: 8*6/4-3+3 and this will still work. It also will not crash if a letter (d, a, s) is entered. Very compact.

Code (Python v3.3.0):

valid_chars = "0123456789-+/* \n";
while True:
    x = "x="
    y = input(" >> ")
    x += y
    if False in [c in valid_chars for c in y]:
        print("WARNING: Invalid Equation");
        continue;
    if(y == "end"):
        break
    exec(x)
    print(x)