평가를 위해 문자열을 변경하는 더 좋은 방법이 있습니까

Question

나누기에서 부동 소수점 숫자로 변경하는 더 좋은 방법이 있습니까? 현재 '/'기호에 대한 내 방정식을 스캔하는 루프가 하나 있고 '/'다음에 숫자를 가져 와서 float으로 변경하는 두 번째 루프가 있습니다. 어떻게 개선 할 수 있습니까?

#!/usr/bin/env python2.7 

import Tkinter as tk 


main = tk.Tk() 
main.title('Calculator') 


def insert_variable(i): 
    """Inserts the user defined sign and puts it on the end the entry widget""" 
    END = len(calc_entry.get()) 
    calc_entry.insert(END,i) 

def calculate(): 
    ''' deletes all characters in the entry and inserts evaluation of the equation ''' 
    equation = calc_entry.get() 
    try: 
     calc_entry.delete(0, len(equation)) # deletes all characters in the entry 
     for i in range(len(equation)-1):# loop for checking for special signs 


      if equation[i] == '/': #if there is '/' sign change one of numbers to float 
       for j in range(i+1,len(equation)): # loop for number of digits after '/' sign 
        if equation[j] == '.': # if there is dot go ones more 
         pass 
        else: 
         try: 
          int(equation[j])# if there is something other than digit go to exception 
         except ValueError: 
          equation = equation[:i+1] + str(float(equation[i+1:j])) + equation[j:]# change number after/to float and join all strings 
          break 

      if equation[i] == '^': # if there is^sign change it for '**' 
       equation = equation[:i] +'**'+ equation[i+1:] 
       print equation 


     calc_entry.insert(0, str(round(eval(equation), 3))) # evaluates (calculates) the equation after loop 

    except SyntaxError: 
     calc_entry.insert(0,'<ERROR>') 
    except ZeroDivisionError: 
     calc_entry.insert(0,'ERROR DIVISION BY 0') 

calc_entry = tk.Entry(main) # creates an entry 
calc_entry.grid(row =1, columnspan = 6) 


bEquate = tk.Button(main, text="=", command = calculate) 
bEquate.grid(row=5, column=3) 

bDivision = tk.Button(main, text="/", command = lambda : insert_variable("/")) 
bDivision.grid(row=3, column=5) 

main.mainloop() 

내가 마지막 번호에 SQRT 기호를 제공 sqrt() 기능이 있다면? 어떻게하면 calculate() 함수로 구현할 수 있습니까?

sqrtChr = unichr(0x221A) 
def insert_sqrt(): 
    """inserts sqrt sign""" 
    global sqrtChr 
    END = len(calc_entry.get()) 
    equation = calc_entry.get() # takes the whole user's equation from the entry 
    for i in range(-1,-END-1,-1): # loop that goes from -1,-2,-3 to end-1 
     if i == -END: # if there are no exceptions like '.' or special sign, inserts sqrt character at beginning of string in the entry 
      calc_entry.insert(0,sqrtChr) 
     elif equation[i] == '.': # if there is a dot in equation go to next character in equation 
      pass 
     else: 
      try: # if there is a sign insert sqrt character after it and break loop 
       int(equation[i]) 
      except ValueError: 
       calc_entry.insert((END+i+1),sqrtChr) 
       break 

Answer 1

사용

from __future__ import division 

및 1/2 의지는 당신에게 0.5을 제공합니다 - 같은 eval("1/2")