小学四则运算编程实践

from generator import Ari_Expression
from infixTosuffix import infix_to_suffix
import Calculate

def main():
max_num = int(input('请输入操作数的最大值：'))
problem = int(input('请输入需要的题目数量：'))
i = 1
correct = []
wrong = []
p = open('Exercises.txt', 'w')
r = open('Answer.txt', 'w')
while i < problem + 1:
ari = Ari_Expression(max_num)
inf = infix_to_suffix()
real_res = Calculate.getResult(inf.str_to_fraction(inf.to_suffix_expression(ari.str)))
if real_res >= 0:
real_res = ari.str_num(real_res)
print(str(i)+'. ' + ari.str, end = '')
p.write(str(i)+'. ' + ari.str + ' ')
r.write(str(i)+'. ' + real_res + ' ')
res = input()
if res == real_res:
correct.append(i)
else:
wrong.append(i)
i += 1
p.close()
r.close()
print('题目正确率：' + str(len(correct)/problem))
g = open('Grade.txt','w')
g.write('Correct:' + str(len(correct))+'(')
for x in correct:
g.write(str(x)+', ')
g.write(') ')
g.write('Wrong:' + str(len(wrong))+'(')
for x in wrong:
g.write(str(x)+', ')
g.write(') ')

if name == 'main':
main()

模块一（Calculate.py)

from fractions import Fraction

import Stack

def getResult(expression):
stackValue = []
for item in expression:
if item in ["+", "-", "×", "÷"]:
n2 = stackValue.pop()
n1 = stackValue.pop()
result = cal(n1, n2, item)
if result < 0:
return -1
stackValue.append(result)
else:
stackValue.append(item)
return stackValue[0]

def cal(n1, n2, op):
if op == "+":
return n1 + n2
if op == "-":
return n1 - n2
if op == "×":
return n1 * n2
if op == "÷":
return n1 / n2

模块二（generator.py）

from fractions import Fraction
import random

class Ari_Expression():
'''算术表达式的生成'''

def __init__(self, max_num):
    self.init_operators()
    self.init_nums(max_num)
    self.init_expression()

def init_num(self, max_num):
    '''随机生成数'''
    denominator = random.randint(1, max_num)
    numerator = random.randint(0, max_num)
    return Fraction(numerator, denominator)

def insert_bracket(self):
    '''插入括号'''
    bracket = ['(', 'null', ')']
    if len(self.operators) > 1:
        x = random.randint(0, len(self.operators))
        while x < len(self.operators):
            y = random.randint(x, len(self.operators))
            low = False
            for a in self.operators[x:y + 1]:
                if a in ['+', '-']:
                    low = True
                    break
            try:
                if self.operators[y + 1] in ['×', '÷'] and low:
                    self.operators.insert(x, '(')
                    self.operators.insert(y + 2, ')')
            except IndexError:
                pass
            x = y + 2

def init_operators(self):
    '''随机生成一个运算符并随机插入括号'''
    self.operators = []
    operator = ['+', '-', '×', '÷', 'null']
    for x in range(3):
        if x == 1:
            self.operators.append(random.choice(operator[:-2]))
        else:
            y = random.choice(operator)
            if y != 'null':
                self.operators.append(y)
    self.insert_bracket()

def init_nums(self, max_num):
    self.nums = []
    self.nums.append(self.init_num(max_num))
    for x in range(len(self.operators)):
        y = self.init_num(max_num)
        if self.operators[x] == '÷':
            while y.numerator == 0:
                y = self.init_num(max_num)
        self.nums.append(y)

def str_num(self, num):
    '''字符串化一个分数'''
    inter = int(num.numerator / num.denominator)
    numerator = int(num.numerator % num.denominator)
    str_num = ''
    if numerator != 0:
        str_num += str(numerator) + '/' + str(num.denominator)
    if not str_num:
        '''如果为空'''
        str_num += str(inter)
    else:
        if inter == 0:
            return str_num
        else:
            str_num = str(inter) + '`' + str_num
    return str_num

def init_expression(self):
    '''生成一个算术表达式的字符串形式'''
    self.str = ''
    i = 0
    self.exp = []
    again = False
    for x in self.operators:
        if again:
            self.str += x + ' '
        elif x == '(':
            self.str += x + ' '
        elif x == ')':
            self.str += self.str_num(self.nums[i]) + ' '
            i += 1
            self.str += x + ' '
            again = True
        else:
            self.str += self.str_num(self.nums[i]) + ' '
            self.str += x + ' '
            i += 1
    self.str += self.str_num(self.nums[-1]) + ' ='

模块三（infixTosuffix.py）

import Stack
from fractions import Fraction

class infix_to_suffix:
def init(self):
self.list_operators = ["+", "-", "×", "÷", "(", ")", "="]
self.pri_operators = {"+": 0, "-": 0, "×": 1, "÷": 1}

def to_suffix_expression(self, expression):
    '''生成逆波兰表达式'''
    stack_operator = Stack.Stack()
    suffix_expression = []
    list_temp = []
    expression = expression + "="
    for element in expression:
        if element not in self.list_operators:
            list_temp.append(element)
        elif element == "=":
            if len(list_temp) != 0:
                str_temp = ""
                for i in range(0, len(list_temp)):
                    str_temp = str_temp+list_temp.pop(0)
                suffix_expression.append(str_temp)
        else:
            if len(list_temp) != 0:
                str_temp = ""
                for i in range(0, len(list_temp)):
                    str_temp = str_temp+list_temp.pop(0)
                suffix_expression.append(str_temp)
            if stack_operator.isEmpty() or element == "(":
                stack_operator.push(element)
            elif element != "(" and element != ")":
                if stack_operator.peek() != "(" and self.pri_operators[element] > self.pri_operators[
                    stack_operator.peek()]:
                    stack_operator.push(element)
                else:
                    while True:
                        if stack_operator.peek() == "(":
                            stack_operator.push(element)
                            break
                        elif self.pri_operators[element] < self.pri_operators[stack_operator.peek()]:
                            while not stack_operator.isEmpty() and True:
                                str_operator = stack_operator.peek()
                                if str_operator == "(" or self.pri_operators[str_operator] < self.pri_operators[
                                    element]:
                                    break
                                else:
                                    stack_operator.pop()
                                    suffix_expression.append(str_operator)
                        else:
                            suffix_expression.append(stack_operator.pop())
                        if stack_operator.isEmpty():
                            stack_operator.push(element)
                            break
            elif element == ")":
                while True:
                    if stack_operator.peek() != "(":
                        suffix_expression.append(stack_operator.pop())
                    else:
                        stack_operator.pop()
                        break
            else:
                stack_operator.push(element)
    if not stack_operator.isEmpty():
        while not stack_operator.isEmpty():
            suffix_expression.append(stack_operator.pop())
    return suffix_expression

def str_to_fraction(self, suf):
    '''字符串转换为fraction类'''
    for x in range(len(suf)):
        if suf[x] not in self.list_operators:
            y = suf[x].strip()
            if y.find('`') == -1:
                if y.find('/') == -1:
                    numerator =  int(y)
                    denominator = 1
                else:
                    a = y.split('/')
                    numerator = int(a[0])
                    denominator = int(a[1])
            else:
                a = y.split('`')
                inter = int(a[0])
                b = a[1].split('/')
                denominator = int(b[1])
                numerator = int(b[0]) + inter * denominator
            new_num = Fraction(numerator,denominator)
            suf[x] = new_num
    return suf

模块四（Stack.py)

class Stack:
"""模拟栈"def __init__(self):

    self.items = []

def isEmpty(self):
    return len(self.items) == 0

def push(self, item):
    self.items.append(item)

def pop(self):
    return self.items.pop()

def peek(self):
    if not self.isEmpty():
        return self.items[len(self.items) - 1]

def size(self):
    return len(self.items)

代码搬运自python结对编程实现小学生四则运算生成器_aokui4738的博客-CSDN博客