Calculator development requirements
- Realize addition, subtraction, multiplication and division and extension number priority analysis
- User input 1 - 2 * ( (60-30 +(-40/5) * (9-2*5/3 + 7 /3*99/4*2998 +10 * 568/14 )) - (-4* 3)/ (16-3*2) ) and other similar formulas, you must parse the (),+,-,*,/ symbols and formulas inside by yourself, and get the result after the operation, and the result must be the same as that obtained by the real calculator results are consistent.
1 # 1. The formula used to calculate a+b. where a and b are integers or finite decimals. No spaces and parentheses. There are no other four calculations. 2 3 4 import re,functools 5 6 def addtion(): 7 formula = input( " Please enter a formula (strictly according to a+b) format: " ) #Get a formula string 8 num_list = re.split( " \ + " ,formula) #It should be noted here that the plus sign is a meta character, and an escape character must be added before it. The result is a list [a,b] 9 print (num_list) 10 return float(num_list[0]) + float(num_list[1 ]) 11 12 print (addtion())