完整的代码如下：

# -*- coding: utf-8 -*-import itertools#with bracketsdef with_brackets(lst, ops_lst):    for op in ops_lst: #无括号时的运算情形        expr1 = '('+lst[0]+op[0]+lst[1]+')'+op[1]+lst[2]+op[2]+lst[3]        expr2 = '('+lst[0]+op[0]+lst[1]+op[1]+lst[2]+')'+op[2]+lst[3]        expr3 = lst[0]+op[0]+'('+lst[1]+op[1]+lst[2]+')'+op[2]+lst[3]        expr4 = '('+lst[0]+op[0]+lst[1]+')'+op[1]+'('+lst[2]+op[2]+lst[3]+')'        for expr in [expr1, expr2, expr3, expr4]:            try:                t=eval(expr)            except: #作除法时，跳过分母为0时的情形                pass            if abs(t-24) < 0.001:#float型数值计算存在微小的误差                return expr    return 0#返回4个数计算24的方法def hasMethod(numbers, ops_lst):    for lst in itertools.permutations(numbers):        lst = list(map(lambda x:str(x), lst))        #without brackets        for op in ops_lst:            expr = lst[0]+op[0]+lst[1]+op[1]+lst[2]+op[2]+lst[3]            if abs(eval(expr)-24) < 0.001:                return expr        #with brackets        expr = with_brackets(lst, ops_lst)        if expr != 0:            return expr    return 0#返回4个数计算24的方法，无方法时返回"No Method"def cal_24(numbers):    ops = ['+','-','*','/']    ops_lst = [[i,j,k] for i in ops for j in ops for k in ops]    expr = hasMethod(numbers, ops_lst)    if expr != 0:        return expr    else:        return 'No method!'#所有情况的计算24点的办法，并输出到文本文件def main():    outfile=open("H:\\24dian.txt","w")    numbers_lst = [[i,j,k,l] for i in range(1,14) for j in range(1,14)\                             for k in range(1,14) for l in range(1,14)]    for numbers in numbers_lst:        a = list(map(lambda x: str(x), numbers))        methodInfo = "[%s,%s,%s,%s]: %s\n"%(a[0],a[1],a[2],a[3],cal_24(numbers))        outfile.write(methodInfo)    outfile.close()    main()

输出的文件如下：