编写程序制作英文学习词典，实现3个基本功能。添加，查询和退出。
以下是该词典的Python代码：
dict = {}
digits = '0123456789'
path = 'dict.txt'
def readFile(path, arg):
try:
file = open(path,arg,encoding = "utf-8")
except:
file = open(path,'w',encoding= "utf-8")
return file
def readWords():
file = readFile(path, 'r')
while True:
line = file.readline()
if not line:
break
word = line.split(' ',2)
dict[word[0]] = word[1][:-1]
file.close()
def writeFile(word,dsp):
file = readFile(path,'a')
file.write('{} {}n'.format(word, dsp))
file.close()
def modifyFile(word, dsp):
file = readFile(path,'r')
line = file.readlines()
flen = len(line) -1
for i in range(flen):
if word in line[i]:
file.close()
line[i] = '{} {}n'.format(word, dsp)
file = readFile(path,'w')
file.writelines(line)
break
file.close()
def editMode():
print('*'*50)
print('*'*50)
while True:
word = input("(按数字键退出)请输入想添加或修改的单词")
if word in digits:
print('*'*50)
print('*'*50)
return
try:
print("该单词已经存在,当前解释是：{}".format(dict[word]))
except:
print('您添加的是一个新单词')
print("-----------------------")
description = input("输入解释：n")
try:
dict[word] += ',%s'%description
modifyFile(word, dict[word])
except KeyError:
dict[word] = '%s'%description
writeFile(word,dict[word])
print('----------------添加完成---------------')
def searchMode():
print('*'*50)
print('*'*50)
while True:
word = input("(按数字键退出)想查的单词：")
if word in digits:
print('*'*50)
print('*'*50)
return
print("-----------------------------------")
try:
print(dict[word])
except KeyError:
print('对不起，这个单词未收录')
print("------------------------------------------")
def interface():
readWords()
def switch(option):
funcdic={
1:lambda :searchMode(),
2:lambda :editMode(),
3:lambda :exit()
}
return funcdic[option]()
while True:
print("-------------欢迎使用-------------")
print("1.查询单词n2.添加单词n3.退出n")
option =int(input("请输入选择："))
switch(option)
interface()
