Python技巧----函数作为参数以及dict代替if

LXY3800

　　这是tkinter的代码，command参数表示按钮对应的动作，这个参数是个函数

# 操作符按钮
self.btn_add = tk.Button(self.tkwindow, text='+', command=self.command_add)
self.btn_add.pack(padx=1, side='left')
self.btn_minus = tk.Button(self.tkwindow, text='-', command=self.command_minus)
self.btn_minus.pack(padx=1, side='left')
self.btn_multiply = tk.Button(self.tkwindow, text='*', command=self.command_multipy)
self.btn_multiply.pack(padx=1, side='left')
self.btn_divide = tk.Button(self.tkwindow, text='/', command=self.command_divide)
self.btn_divide.pack(padx=1, side='left')
'''
省略
'''
def command_add(self):
if self.op_can_use:
self.op_now = '+'
self.op_pressed = True
def command_minus(self):
if self.op_can_use:
self.op_now = '-'
self.op_pressed = True
def command_multipy(self):
if self.op_can_use:
self.op_now = '*'
self.op_pressed = True
def command_divide(self):
if self.op_can_use:
self.op_now = '/'
self.op_pressed = True

　　但这4个command的函数几乎长得一模一样啊，有四个还好，如果有十几个怎么办，能不能精简点

    def command_op(self, op):
if self.op_can_use:
self.op_now = op
self.op_pressed = True
def command_add(self):
return self.command_op('+')
def command_minus(self):
return self.command_op('-')
def command_multipy(self):
return self.command_op('*')
def command_divide(self):
return self.command_op('/')   

　　和dict配合使用

self.opdict = {'+': add, '-': minus, '*': multiply, '/': divide}

#这是调用，根据op_now选择对应的函数，代替if判断
self.opnum = self.opdict[self.op_now](self.opnum, self.num_temp)[0]
　　全部代码，计算24点，用tkinter做了界面，两个文件一个界面，一个计算24点的函数

# enconding:utf-8
# file point24/gui
import tkinter as tk
import random
from point24.bk import cal_24point, add, minus, multiply, divide
class Window:
def __init__(self, title='24点', width=650, height=400):
self.w = width
self.h = height
self.tkwindow = tk.Tk(className=title)
self.opdict = {'+': add, '-': minus, '*': multiply, '/': divide}
self.init_status()
self.add_compnent()
def init_status(self):

self.op_pressed = False
self.op_now = ''
self.opnum = 0
self.num_temp = 0
self.num_count = 0
self.op_can_use = False
self.btn_num_temp_used = False
def fournumber(self):
TEN_OR_K = 10
self.num1 = random.randint(1, TEN_OR_K)
self.num2 = random.randint(1, TEN_OR_K)
self.num3 = random.randint(1, TEN_OR_K)
self.num4 = random.randint(1, TEN_OR_K)
def add_compnent(self):
B_WIDTH = 6
B_HEIGHT = 5
self.label_ans = tk.Label(text="answer", fg="black", bg="white")
self.label_ans.pack()
# 数字按钮
self.fournumber()
self.btn_num1 = tk.Button(self.tkwindow, text=self.num1,
command=self.command_num1,
width=B_WIDTH, height=B_HEIGHT,relief='groove')
self.btn_num1.pack(side='left')
self.btn_num2 = tk.Button(self.tkwindow, text=self.num2,
command=self.command_num2,
width=B_WIDTH, height=B_HEIGHT,relief='groove')
self.btn_num2.pack(side='left')
self.btn_num3 = tk.Button(self.tkwindow, text=self.num3,
command=self.command_num3,
width=B_WIDTH, height=B_HEIGHT,relief='groove')
self.btn_num3.pack(side='left')
self.btn_num4 = tk.Button(self.tkwindow, text=self.num4,
command=self.command_num4,
width=B_WIDTH, height=B_HEIGHT,relief='groove')
self.btn_num4.pack(side='left')
self.btn_num_temp = tk.Button(self.tkwindow, text=self.num_temp,
command=self.command_num_temp,
width=B_WIDTH, height=B_HEIGHT,relief='groove')
self.btn_num_temp.pack(side='bottom')
# 操作符按钮
self.btn_add = tk.Button(self.tkwindow, text='+',
command=self.command_add,
width=B_WIDTH, height=B_HEIGHT,relief='groove')
self.btn_add.pack(padx=1, side='left')
self.btn_minus = tk.Button(self.tkwindow, text='-',
command=self.command_minus,
width=B_WIDTH, height=B_HEIGHT,relief='groove')
self.btn_minus.pack(padx=1, side='left')
self.btn_multiply = tk.Button(self.tkwindow, text='*',
command=self.command_multipy,
width=B_WIDTH, height=B_HEIGHT,relief='groove')
self.btn_multiply.pack(padx=1, side='left')
self.btn_divide = tk.Button(self.tkwindow, text='/',
command=self.command_divide,
width=B_WIDTH, height=B_HEIGHT,relief='groove')
self.btn_divide.pack(padx=1, side='left')
# 功能按钮
self.btn_change = tk.Button(self.tkwindow, text='换一组',
command=self.command_change,
width=B_WIDTH, height=B_HEIGHT,relief='groove')
self.btn_change.pack(padx=1, side='right')
self.btn_answer = tk.Button(self.tkwindow, text='显示答案',
command=self.command_answer,
width=B_WIDTH, height=B_HEIGHT,relief='groove')
self.btn_answer.pack(padx=1, side='right')
self.btn_clear = tk.Button(self.tkwindow, text='清除',
command=self.command_clear,
width=B_WIDTH, height=B_HEIGHT,relief='groove')
self.btn_clear.pack(padx=1, side='right')
# 一个数字只能按一次，按错了用clear重来
def command_clear(self):
self.btn_num1['state'] = 'active'
self.btn_num2['state'] = 'active'
self.btn_num3['state'] = 'active'
self.btn_num4['state'] = 'active'
self.btn_num_temp['state'] = 'active'
self.btn_num_temp['text'] = '0'
self.label_ans['text'] = 'answer'
self.init_status()
def command_answer(self):
ans = cal_24point(self.num1, self.num2, self.num3, self.num4)
self.label_ans['text'] = str(ans)
def command_change(self):
self.fournumber()
self.btn_num1['text'] = self.num1
self.btn_num2['text'] = self.num2
self.btn_num3['text'] = self.num3
self.btn_num4['text'] = self.num4
self.command_clear()
def command_op(self, op):
if self.op_can_use:
self.op_now = op
self.op_pressed = True
def command_add(self):
return self.command_op('+')
def command_minus(self):
return self.command_op('-')
def command_multipy(self):
return self.command_op('*')
def command_divide(self):
return self.command_op('/')   
def command_num_temp(self):
if self.op_pressed:
self.opnum = self.opdict[self.op_now](self.opnum, self.num_temp)[0]
self.btn_num_temp['text'] = self.opnum
self.num_temp = self.opnum
else:
self.opnum = self.num_temp
print(self.opnum)
self.op_pressed = False
self.btn_num_temp['state'] = 'disabled'
if self.opnum == 24:
self.label_ans['text'] = 'right'
def command_numwhich(self, num, btn_num):
if self.op_pressed:
self.opnum = self.opdict[self.op_now](self.opnum, num)[0]
if not self.btn_num_temp_used:
self.btn_num_temp['text'] = self.opnum
self.num_temp = self.opnum
self.btn_num_temp_used = True
else:
self.opnum = num
print(self.opnum)
self.op_pressed = False
btn_num['state'] = 'disabled'
self.op_can_use = True
self.num_count += 1
if self.opnum == 24 and self.num_count ==4:
self.label_ans['text'] = 'right'
def command_num1(self):
return self.command_numwhich(self.num1, self.btn_num1)
def command_num2(self):
return self.command_numwhich(self.num2, self.btn_num2)
def command_num3(self):
return self.command_numwhich(self.num3, self.btn_num3)
def command_num4(self):
return self.command_numwhich(self.num4, self.btn_num4)
def center(self):
ws = self.tkwindow.winfo_screenwidth()
hs = self.tkwindow.winfo_screenheight()
x = int((ws/2)-(self.w/2))
y = int((hs/2)-(self.h/2))
self.tkwindow.geometry('{}x{}+{}+{}'.format(self.w, self.h, x, y))
def loop(self):
self.tkwindow.resizable(False, False)
self.center()
self.tkwindow.mainloop()
# ##############################run##################################
w = Window()
w.loop()


# encoding:utf-8
# file point24/bk
import itertools
import random
def add(a, b):
return a+b, str(a)+'+'+str(b)+'='+str(a+b)
def minus(a, b):
# 打印答案时不要有负数
if a<b:
return 9999, 'no'
return a-b, str(a)+'-'+str(b)+'='+str(a-b)
def multiply(a, b):
return a*b, str(a)+'*'+str(b)+'='+str(a*b)
def divide(a, b):
if b == 0:
return 9999, 'no'
return a/b, str(a)+'/'+str(b)+'='+str(a/b)

def cal_24point(a, b, c, d):
# a, b, c, d的排列组合
permutation_list = list(itertools.permutations([a, b, c, d], 4))  
# 加减乘除 排列组合
op_list = list(itertools.permutations([add, minus, multiply, divide], 4))  
# pro1 到 pro5包装函数
# ((a, b), c), d
def pro1(op1, op2, op3):
m = op1(pmt[0], pmt[1])
n = op2(m[0], pmt[2])
result = op3(n[0], pmt[3])
if result[0] == 24:
#print(m[1], n[1], result[1])
return (m[1], n[1], result[1])
# (c, (a, b)), d   
def pro2(op1, op2, op3):
m = op1(pmt[0], pmt[1])
n = op2(pmt[2] , m[0])
result = op3(n[0], pmt[3])
if result[0] == 24:
#print(m[1], n[1], result[1])
return (m[1], n[1], result[1])
# d, ((a, b), c)
def pro3(op1, op2, op3):
m = op1(pmt[0], pmt[1])
n = op2(m[0], pmt[2])
result = op3(pmt[3], n[0])
if result[0] == 24:
#print(m[1], n[1], result[1])
return (m[1], n[1], result[1])
# d, (c, (a, b))
def pro4(op1, op2, op3):
m = op1(pmt[0], pmt[1])
n = op2(pmt[2], m[0])
result = op3(pmt[3], n[0])
if result[0] == 24:
#print(m[1], n[1], result[1])
return (m[1], n[1], result[1])
# (a b)(c d)
def pro5(op1, op2, op3):
m = op1(pmt[0], pmt[1])
n = op2(pmt[2], pmt[3])
result = op3(n[0], m[0])
if result[0] == 24:
#print(m[1], n[1], result[1])
return (m[1], n[1], result[1])
for pmt in permutation_list:
for op in op_list:
# 相同运算符
if pro1(op[0], op[0], op[0]):
return pro1(op[0], op[0], op[0])
if pro2(op[0], op[0], op[0]):
return pro2(op[0], op[0], op[0])
if pro3(op[0], op[0], op[0]):
return pro3(op[0], op[0], op[0])
if pro4(op[0], op[0], op[0]):
return pro4(op[0], op[0], op[0])
if pro5(op[0], op[0], op[0]):
return pro5(op[0], op[0], op[0])
# ((a, b), c), d
if pro1(op[0], op[1], op[2]):
return pro1(op[0], op[1], op[2])
if pro1(op[0], op[1], op[1]):
return pro1(op[0], op[1], op[1])
if pro1(op[0], op[0], op[1]):
return pro1(op[0], op[0], op[1])
if pro1(op[0], op[1], op[0]):
return pro1(op[0], op[1], op[0])
# (c, (a, b)), d
if pro2(op[0], op[1], op[2]):
return pro2(op[0], op[1], op[2])
if pro2(op[0], op[1], op[1]):
return pro2(op[0], op[1], op[1])
if pro2(op[0], op[0], op[1]):
return pro2(op[0], op[0], op[1])
if pro2(op[0], op[1], op[0]):
return pro2(op[0], op[1], op[0])
# d, ((a, b), c)
if pro3(op[0], op[1], op[2]):
return pro3(op[0], op[1], op[2])
if pro3(op[0], op[1], op[1]):
return pro3(op[0], op[1], op[1])
if pro3(op[0], op[0], op[1]):
return pro3(op[0], op[0], op[1])
if pro3(op[0], op[1], op[0]):
return pro3(op[0], op[1], op[0])
# d, (c, (a, b))
if pro4(op[0], op[1], op[2]):
return pro4(op[0], op[1], op[2])
if pro4(op[0], op[1], op[1]):
return pro4(op[0], op[1], op[1])
if pro4(op[0], op[0], op[1]):
return pro4(op[0], op[0], op[1])
if pro4(op[0], op[1], op[0]):
return pro4(op[0], op[1], op[0])
# (a b)(c d)
if pro5(op[0], op[1], op[2]):
return pro5(op[0], op[1], op[2])
if pro5(op[0], op[1], op[1]):
return pro5(op[0], op[1], op[1])
if pro5(op[0], op[0], op[1]):
return pro5(op[0], op[0], op[1])
if pro5(op[0], op[1], op[0]):
return pro5(op[0], op[1], op[0])
print('no result')
return None

# ---------------------------test---------------------------------
'''
for n in range(30):
a = random.randint(1,13)
b = random.randint(1,13)
c = random.randint(1,13)
d = random.randint(1,13)
print(a, b, c, d)
print(cal_24point(a, b, c, d),'*'*10)
'''

　　界面是难看了点 ，哈哈哈哈