计算器

 1 #计算一个表达式的时候，首先肯定是先算括号里面的，再算乘除法，后算加减法
 2 import re
 3 # 1.去括号
 4 def remove_kuohao(expression):
 5     ‘‘‘
 6     这是一个去除括号的函数
 7     :param expression:  传进来的表达式
 8     :return: 计算后的结果
 9     ‘‘‘
10     while True:
11         ret = re.search(r‘\([^(]*?\)‘,expression) #先利用正则匹配到式子里面的括号
12         if ret: #如果有括号
13             re_expression = ret.group()  #先把找到的括号group()一下得到
14             # print(re_expression)
15             res = jianhua(re_expression.strip(‘()‘))  #括号里面有*/-+都不一定，就又定义了一个简化这个表达式的函数
16             # 如果是乘法就执行乘法运算，如果是除法运算就执行除法等，这样的话就直接调用jianhua这个函数了，当然这个式子
17             # 有括号，顺便把括号也去了，直接计算去掉括号后的式子
18             expression = expression.replace(re_expression,str(res))  #把计算出来的结果放回去：就是把原来的括号里的表达式
19                                                                     # 替换成现在计算的结果
20             # print(expression)
21             continue
22         break
23     res = jianhua(expression)
24     return res
25 #简化算法
26 def jianhua(re_expression):
27     while True:
28         # 匹配乘除法
29         ret = re.search(r‘\d+\.*?\d*[*/]\-?\d+\.?\d*‘, re_expression) #利用正则匹配乘除法
30         if ret:  # 如果匹配到有*或/就执行下面的代码
31             chengchu_expression = ret.group() #就先group一下得到有乘除法的表达式
32             res = chengchu(chengchu_expression)  #调用乘除法的函数计算
33             re_expression = re_expression.replace(chengchu_expression, str(res))  #吧有乘除法的表达式和计算出来的结果替换
34             re_expression =chulifuhao(re_expression)  #在调用处理符号的函数
35             # print(re_expression)
36             continue
37         break
38     # 匹配加减法
39     num = re.findall(r‘[+-]?\d+\.?\d*‘, re_expression)#在没有乘除法的时候，就让匹配加减法，
40     if len(num) > 1:  #如果匹配到的表达式的长度大于1，不过是加法还是减法，都让计算加法。因为float啥结果就是啥
41         mynum = 0
42         for i in num:
43             mynum += float(i)
44         return mynum
45     else:
46         return num[0]
47 # 3.计算两个数的+-*/
48 def chengchu(expression):
49     if ‘*‘ in expression:
50         x,y = expression.split(‘*‘)
51         return float(x)*float(y)  #返回乘法运算的结果 ，让res接收
52     if ‘/‘ in expression:
53         x, y = expression.split(‘/‘)
54         return float(x)/float(y)   #返回乘法运算的结果 ，让res接收
55 
56 def chulifuhao(expression):
57     if ‘--‘ in expression:
58        expression = expression.replace(‘--‘,‘+‘)
59     if ‘++‘ in expression:
60         expression = expression.replace(‘++‘,‘+‘)
61     if ‘+-‘ in expression:
62        expression = expression.replace(‘+-‘,‘-‘)
63     if ‘-+‘ in expression:
64         expression = expression.replace(‘-+‘,‘-‘)
65     return expression  #返回结果
66 
67 cmd = input(‘请输入你要计算的表达式：>>‘)
68 # s = ‘1 - 2 * ( (60-30 +(-40/5) * (9-2*5/3 + 7 /3*99/4*2998 +10 * 568/14 )) - (-4*3)/ (16-3*2) )‘
69 new_s = cmd.replace(‘ ‘, ‘‘) #先将所有的空格去了
70 # print(new_s)
71 ret = remove_kuohao(new_s)  #调用去除括号的函数，进行下一步操作
72 print(ret)

  1 import re
  2 from functools import reduce
  3 from tkinter import *
  4 ‘‘‘处理特殊－号运算‘‘‘
  5 
  6 
  7 def minus_operation(expresstion):
  8     minus_operators = re.split("-", expresstion)
  9     calc_list = re.findall("[0-9]", expresstion)
 10     if minus_operators[0] == "":
 11         calc_list[0] = ‘-%s‘ % calc_list[0]
 12     res = reduce(lambda x, y: float(x) - float(y), calc_list)
 13     print(">>>>>>>>>>>>>>减号[%s]运算结果:" % expresstion, res)
 14     return res
 15 
 16 ‘‘‘reduce()对sequence连续使用function, 如果不给出initial, 则第一次调用传递sequence的两个元素,
 17 以后把前一次调用的结果和sequence的下一个元素传递给function‘‘‘
 18 
 19 ‘‘‘处理双运算符号‘‘‘
 20 
 21 
 22 def del_duplicates(expresstion):
 23     expresstion = expresstion.replace("++", "+")
 24     expresstion = expresstion.replace("--", "-")
 25     expresstion = expresstion.replace("+-", "-")
 26     expresstion = expresstion.replace("--", "+")
 27     expresstion = expresstion.replace(‘- -‘, "+")
 28     return expresstion
 29 ‘‘‘＊／运算函数‘‘‘
 30 def mutiply_dividend(expresstion):
 31     calc_list = re.split("[*/]", expresstion)  # 用＊ or /分割公式
 32     operators = re.findall("[*/]", expresstion)  # 找出所有＊和／号
 33     res = None
 34     for index, i in enumerate(calc_list):
 35         if res:
 36             if operators[index - 1] == ‘*‘:
 37                 res *= float(i)
 38             elif operators[index - 1] == ‘/‘:
 39                 res /= float(i)
 40         else:
 41             res = float(i)
 42     procession0 = "[%s]运算结果=" % expresstion, res
 43     # final_result.insert(END, procession0)  # 插入窗体
 44     print(procession0)
 45     return res
 46 
 47 ‘‘‘处理运算符号顺序混乱情况‘‘‘
 48 def special_features(plus_and_minus_operators, multiply_and_dividend):
 49     for index, i in enumerate(multiply_and_dividend):
 50         i = i.strip()
 51         if i.endswith("*") or i.endswith("/"):
 52             multiply_and_dividend[index] = multiply_and_dividend[index] + plus_and_minus_operators[index] + multiply_and_dividend[index + 1]
 53             del multiply_and_dividend[index + 1]
 54             del plus_and_minus_operators[index]
 55         return plus_and_minus_operators, multiply_and_dividend
 56 
 57 def minus_special(operator_list, calc_list):
 58     for index, i in enumerate(calc_list):
 59         if i == ‘‘:
 60             calc_list[index + 1] = i + calc_list[index + 1].strip()
 61 ‘‘‘运算除了（）的公式＋－＊／‘‘‘
 62 def figure_up(expresstion):
 63     expresstion = expresstion.strip("()")  # 去掉外面括号
 64     expresstion = del_duplicates(expresstion)  # 去掉重复＋－号
 65     plus_and_minus_operators = re.findall("[+-]", expresstion)
 66     multiply_and_dividend = re.split("[+-]", expresstion)
 67     if len(multiply_and_dividend[0].strip()) == 0:
 68         multiply_and_dividend[1] = plus_and_minus_operators[0] + multiply_and_dividend[1]
 69         del multiply_and_dividend[0]
 70         del plus_and_minus_operators[0]
 71     plus_and_minus_operators, multiply_and_dividend = special_features(plus_and_minus_operators, multiply_and_dividend)
 72     for index, i in enumerate(multiply_and_dividend):
 73         if re.search("[*/]", i):
 74             sub_res = mutiply_dividend(i)
 75             multiply_and_dividend[index] = sub_res
 76     # print(multiply_and_dividend, plus_and_minus_operators)  # 计算
 77     final_res = None
 78     for index, item in enumerate(multiply_and_dividend):
 79         if final_res:
 80             if plus_and_minus_operators[index - 1] == ‘+‘:
 81                 final_res += float(item)
 82             elif plus_and_minus_operators[index - 1] == ‘-‘:
 83                 final_res -= float(item)
 84         else:
 85             final_res = float(item)
 86             procession = ‘[%s]计算结果:‘ % expresstion, final_res
 87         # final_result.insert(END, procession)  # 插入窗体
 88         # print(procession)
 89     return final_res
 90 """主函数：运算逻辑：先计算拓号里的值,算出来后再算乘除,再算加减"""
 91 def calculate():
 92     expresstion = expresstions.get()  # 获取输入框值
 93     flage = True
 94     calculate_res = None  # 初始化计算结果为None
 95     while flage:
 96         m = re.search("\([^()]*\)", expresstion)  # 先找最里层的（）
 97     # pattern = re.compile(r"\([^()]*\)")
 98     # m = pattern.match(expresstion)
 99         if m:
100             sub_res = figure_up(m.group())  # 运算（）里的公式
101             expresstion = expresstion.replace(m.group(), str(sub_res))  # 运算完毕把结果替换掉公式
102         else:
103             # print(‘---------------括号已经计算完毕--------------‘)
104             procession1 = "最终计算结果:%s\n"%figure_up(expresstion)
105             print(procession1)
106             final_result.insert(END, procession1)  # 插入窗体
107             # print(‘\033[31m最终计算结果:‘, figure_up(expresstion))
108             flage = False
109 
110 if __name__ == "__main__":
111 # res = calculate("1 - 2 * ( (60-30 +(-40/5) * (9-2*5/3 + 7 /3*99/4*2998 +10 * 568/14 )) - (-4*3)/ (16-3*2) )")
112     window = Tk()  ###创建窗体
113     window.title(‘计算器‘)  ###命名窗体
114     frame1 = Frame(window)  ###框架1
115     frame1.pack()  ###放置
116     frame2 = Frame(window)  ###框架2
117     frame2.pack()  ###放置
118     lable = Label(frame1, text="请输入公式：")  ###文字标签
119     lable.pack()
120     expresstions = StringVar()  ###输入框属性，字符串
121     entryname = Entry(frame1, textvariable=expresstions)  ###文本输入框
122     bt_get_expresstions = Button(frame1, text="提交", command=calculate)  ###按钮挂件
123     bt_get_expresstions.pack()
124     entryname.pack()
125     lable.grid_slaves(row=1,column=1)
126     entryname.grid_slaves(row=1,column=1)
127     bt_get_expresstions.grid_slaves(row=1,column=3)
128     final_result = Text(frame2)  ###计算结果显示框
129     final_result.tag_config("here", background="yellow", foreground="blue")
130     final_result.pack()
131     window.mainloop()  ###事件循环