Python's common built-in sequence structure (list, tuple, dictionary) learning notes

Lists and tuples
The list is expressed in curly braces [], and the tuple is represented by parentheses ().
Lists can be modified, and strings and tuples cannot be modified.
The Shard of a tuple is also a tuple, a shard of a list or a list.

1. List method:

name=["Zhang3", "Li4", "Wang5"]name.append ("Gou6") #添加项name. Remove ("Gou6") #移除第一个匹配项 or del name[3] to remove Name.insert (3 , "Gou6") #插入项name. Index ("Gou6") #找出第一个匹配项的位置name. Extend (["Gou6", "Xuan7"]) #扩展name. Pop (0) #返回列表的第一项值并从列表中删除之

2. List functions:

>>> a=list ("Hi guys") #把字符串转换为列表 >>> print a[' h ', ' I ', ', ' g ', ' u ', ' y ', ' s ']>>> '. Join (a) 
   #把列表还原成字符串 ' Hi guys ' >>> max (a) #取得列表的最大元素 ' y ' >>> len (a) #取得列表长度7 >>> min (a) #取得最小元素 ' > >> tuple (a) #将列表转换为元组 (' h ', ' I ', ', ' g ', ' u ', ' y ', ' s ') >>> sorted (a) #将列表元素排序 ["', ' g ', ' h ', ' I ', ' s ', ' u ' , ' Y ']

3. List traversal:

A, use the For statement to traverse

For Each_item in Name:   print (Each_item)

B, using the while statement to traverse

I=0while i < Len (name):   print (name[i])   i + = 1

4. Membership 1:

>>> sub= "Hello, you is a bear" >>> "Bear" in Subtrue>>> "Y" in Subtrue>>> raw_input ("W Hat ' s your name? ") In Subwhat ' s your name?beartrue

5. Membership 2:

database=[["Zhang3", "0111"],["Li4", "0112"],["Wang5", "0113"]]username=raw_input ("What ' s your user name?") Id=raw_input ("What ' s your ID?") If [Username,id] in Database:print "Access granted"

6. Find the integer within 10

s = [x for x in range (0, ten) if x% 2 = = 0]

7. Generate 99 Multiplication table

s = [(x, Y, X*y) for x in range (1, ten) for Y in range (1,10) if x>=y]

String

1. Get the string

Name=raw_input ("What ' s your name?")      Print "Hello," + name + ". Welcome to US"

Note: pyhton3.x version canceled raw_input, unified use of input
Output value:

Print name + repr (x) #str用于把值转换为合理的字符串, Repr creates a string, returns the string form of the value #str is a type (like int), repr is a function

2. NewLine characters are denoted by \ n
The original string, with an R in front of the string, as

Print R "c:\nowindows\no" Path= "c:\nowindows\no"; Print repr (path)

3.Unicode string

Print U "Redhat"

Note: pyhton3.x version all strings are Unicode strings
When defining a string, double and single quotation marks are available, except that double quotes can be used inside a string when using single quotes
Boolean value:

>>> bool (' I love you ') true>>> bool (true>>>) bool (1) true>>> bool (' 0 ') true> >> bool (0) false>>> bool (") False

4. String methods

>>> tag= "Baidu indexpage" >>> print tag[8:28] #字符串分片http://www.baidu.com>>> print tag[29:-4 ] #字符串分片baidu indexpage>>> tag.replace ("www.baidu.com", "home.sina.com") #字符串替换 ' Baidu Indexpage ' >> > dirs=["", "usr", "bin", "env"]>>> "/". Join (dirs)  #将列表拼接成字符串 '/usr/bin/env ' >>> print ("C:" + " \ \ ". Join (dirs)) c:\usr\bin\env>>> path="/usr/bin/env ">>> path.split ("/") #将字符串分割成列表 [', ' usr ', ' Bin ', ' env ']

5. Other string methods

>>> s= ' I love you!  ' >>> s.lower () #转换字符串的小写 ' I love you!  ' >>> s.upper () #转换字符串的大写 ' I love you!  ' >>> S.title () #换换字符串为标题 (all words capitalized) ' I love you!  ' >>> s.islower () #判断字符串是否为小写 (can also be judged by uppercase and caption) false>>> S.strip ()  #去除首尾空格, Lstrip Remove the left space, Rstrip Remove right space ' I love you! ' >>> word=s.split () #分割 >>> word[' I ', ' love ', ' you! ' >>> ':: '. Join (word) #合并 ' i::love::you! ' >>> s.count (' o ') #统计出现次数2 >>> s.find (' You ') #查找位置, if not found, return -19>>> s.startswith (' python ') False>>> s.replace (' You ', ' yours ') ' I love yours!  '

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