def divide(message):

print("-----------------------------",message,"---------------------------",sep="")

#string字符串类型

#遍历

message = "letter"

i=0

while i < len(message):

print(message[i],end="")#print(end修改结尾类型，sep修改间隔类型)

i+=1

for i in range(len(message)):

print(message[i],end="")

for letter in message:

print(letter,end="")

def reverse(message):

for i in range(len(message)):

print(message[-i-1],end="")#-1标识倒数第一个，-2倒数第二，以此类推

#print("\ntest")

#Index = 1看起来for in range不能自设置起始下标啊

# for Index in range(len(message)):

# print(message[Index],end="")

reverse(message)

#部分遍历？ 划分slice(切片)

print("\n",message[1:5],sep="")#下标1->5的字符

print(message[:4])#下标0->4的字符

print(message[2:])#下标2->end的字符

print(message[3:3])#将会是""

print(message[:])#完全输出

#!!!与c++不同，不能修改字符串的单个字符

#message[0]='p' #TypeError: 'str' object does not support item assignment

#print(message)

#search查找

def find(letter,word):

for i in range(len(word)):

if word[i] == letter:

return i

return -1

#看起来貌似没有类似于c++函数重载的功能，函数名不能重复，即使功能一样

def Find(letter,word,start_index):

while start_index<len(word):

if word[start_index] == letter:

return start_index

start_index+=1

return -1

print(find('e',message))

print(Find('e',message,2))

#count 计数

def count(letter,word):

count_result = 0

for ch in word:

if ch == letter:

#count_result++ 没有自加自减

count_result+=1

return count_result

print(count('e',message))

#字符串类自带的函数

divide("Invocation")

word = "sequence"

print(word.upper())#大写函数

print(word.find('e'))

print(word.find('en',2))#查找子字符串也可以，后一个参数指定起始下标

#in

divide("in")

if 'e' in message:

print(message,"has the letter 'e'.")

def in_both(word_1,word_2):#貌似没有客服重复出现的情况

for letter in word_1:

if letter in word_2:

print(letter,end="")

in_both(message,word)

print()

#compare

divide("Compare")

while True:

message = input("> ")#字符串的比较也是按ASCII码顺序比较的A在前a在后

if message == "message":

print("your input",message,"is same with the key_word i have set")

break

elif message < "message":

print("your input is Smaller")

else:

print("your input is greater")

#Practice

divide("Practice")

def is_reverse(word_1,word_2):

if len(word_1)!=len(word_2):

return False

for i in range(len(word_1)):

if word_1[i]!=word_2[-1-i]:

return False

return True

print(is_reverse("stop","pots"))

print(is_reverse("boring","notfun"))

New_Test_Word = "\tDeco*27\n"

print(New_Test_Word)

New_Test_Word.strip()#delete字符串两端的特殊字符，但是不改变字符串本身，好鸡肋

#New_Test_Word.lstrip() 只删除左侧的特殊字符

#New_Test_Word.rstrip() 只删除右侧的特殊字符

print(New_Test_Word.strip("\t"))#可以指定删除的特殊字符

New_Test_Word.replace('D','d')#修改字符串的字符，修改了，但是原本的不变，也好鸡肋

print(New_Test_Word.replace('D','d'))

def is_palindrome(word):

if word[::-1]==word:return True

#word[a:b:c]a是起始下标，b是终止下标，c是步长，-1标识逆序

else:return False

print(is_palindrome("pop"))

#凯撒加密

divide("caesar")

print(ord('z'),ord('Z'))

print(chr(65),chr(97))

def rotate(word,n):

for letter in word:

if ord(letter)<91 and ord(letter)>64:

print(chr((ord(letter)-64+n)%24+64),end="")

elif ord(letter)<123 and ord(letter)>96:

print(chr((ord(letter)-97+n)%24+97),end="")

else:

print(letter,end="")

print()

rotate("abc",3)

text = input("Please ipnut a setence you want to Caesar:> ")

rotate(text,3)