1.简单计算器

 

 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)

 

计算器

 

2.更高级的计算器

  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

 

窗体计算器