python中列表和元組的操作(結尾格式化輸出小福利)

一. 列表

1. 查

names = "YanFeixu WuYifan"
names_1 = ["YanFeixu"," WuYifan","Zhangsan"]

print(names)
print(names_1[0],names_1[2])
print(names_1[1:2])  # 切片
print(names_1[2])    # 切片
print(names_1[-1])   # 切片
print(names_1[-2:])  # 切片

2. 增

names_1 = ["YanFeixu"," WuYifan","Zhangsan"]
names_1.append("zhansgan")  # 新增
names_1.insert(1,"Lisi")    # 插入索引為1的前面

print(names_1)

3. 改

names_1 = ["YanFeixu"," WuYifan","Zhangsan"]
names_1[2] = "Zhuli"

print(names_1)

4. 刪

names_1 = ["YanFeixu"," WuYifan","Zhangsan","Zhuli"]
names_1.remove("Zhangsan")  # 刪除的第一種方法
del names_1[1]              # 刪除的第二種方法
names_1.pop()               # 默認刪除最后一個

print(names_1)

5. 列表的方法

# 方法
names_1 = ["YanFeixu"," WuYifan","Zhangsan","Zhuli","Zhuli"]

print(names_1.index("Zhuli"))  # 序號
print(names_1 [names_1.index("Zhuli")])  # 把Zhuli打印下來
print(names_1.count("Zhuli"))   # 統計一下有幾個Zhuli

names_1.reverse()  # 把列表反轉，也就是把序號顛倒
print(names_1)

names_1.sort()   # 把列表按字母排序，先是符號，再是數字，再是字母
print(names_1)

names_2 = [1,2,3,4]     # 擴展的方法，列表name_1和name_2合並了
names_1.extend(names_2)
print(names_1,"+",names_2)

import copy
# 方法
names_1 = ["YanFeixu"," WuYifan","Zhangsan",["Wangwu","Zhouliu"],"Zhuli","Zhuli"]
names_2 = names_1.copy()  # 淺copy，只復制第一層，它變我不變（因為已經復制下來了），其余層它變我也變，外面是第一層**
print(names_1)

names_1[2] = "張三"
names_1[3][0] = "王五"
print(names_2)

names_1[2] = "張三"
names_3 = copy.deepcopy(names_1)  # 深copy，就是克隆一份，具有自己單獨的內存地址，兩者完全不相干設，他變我不變
print(names_3)

二、元組

元組其實跟列表差不多，也是存一組數，只不是它一旦創建，便不能再修改，所以又叫只讀列表

語法names = ("YanFeixu","jack","eric")
它只有2個方法，一個是count,一個是index。

小福利：

python中三引號的作用：
1 多行注釋

print('Hello world!')
""" 這是一個 多行注釋 注釋, ### """

2 按照原格式輸出文本（也就是格式化輸出）

a = """ ###pandas features a number of fnctions for reading 'tabular data' as a DataFrame object. Such as , read_csv ...&&&；；；'''hello''' """
print(a)

輸出結果：

3.格式化輸出的案例：
案例（1）

name  = input("name:")
age  = input("age:")
job = input("job")
# 此處的三引號是格式化輸出，不是注釋！
info = '''------info of %s------ Name: %s Age : %s Job: %s ''' % （name,name,age,job）

print(info)

輸出結果：

name:hzangsan
age:12
job:da
------info of hzangsan------
Name: hzangsan
Age : 12
Job: da

案例（2）

name_1 = input("name_1:")
age_1 = input("age_1:")
job_1 = input("job_1:")

info_1 = '''-----info of {name}------ Name: {name} Age: {age} Job: {job} '''.format(name = name_1,
           age = age_1,
           job = job_1)

print(info_1)

輸出結果：

name_1:zhansan
age_1:12
job_1:nishi
-----info of zhansan------
Name: zhansan
Age: 12
Job: nishi

此處有一個關於format的知識點：

username = input("username:")
print ("welcome {name} to our school".format(name = username ))

輸出結果：