课程表

Mafaaani ya Python

• Mafaaani ya Python
• Muhtasari wa Python
• Kuanza Kwa Python
• Majadiliano ya Python
• Mashabiki ya Python
• Vivutio vya Python
• Aina za Data ya Python
• Python 数字
• Kufaaaniwa Kwa Python
• Mawili ya Python
• Boole ya Python
• Maktaba ya Python
• Mifaaani ya Python
• Mafaaani ya Python
• Mafaaani ya Python
• Mafaaani ya Python
• Python If Else
• Makikuu ya While ya Python
• Makikuu ya For ya Python
• Mafaaani ya Functi ya Python
• Lambda ya Python
• Mafaaani ya Array ya Python
• Python 类/对象
• Kununua ya Python
• Muungano wa Python
• Muundo wa Python
• Makuli ya Python
• Tarehe ya Python
• JSON ya Python
• RegEx ya Python
• PIP ya Python
• Try Except ya Python
• Python 命令输入
• Muungaji wa Mawili wa Python

文件处理

• Fungu ya Faili ya Python
• Kureadha Faili ya Python
• Python 文件写入/创建
• Kufaali Faili ya Python

Python NumPy

• Muhtasari wa NumPy
• Kuanza Kwa NumPy
• Uundaji wa Array ya NumPy
• Kichwa cha Array ya NumPy
• Kukataa Array ya NumPy
• Aina za Data ya NumPy
• Kununua na Kusoma Array ya NumPy
• Muundo wa Array ya NumPy
• Umuungaji wa Array ya NumPy
• Muungano wa Array ya NumPy
• Kufaaaniwa wa Array ya NumPy
• Kusababisha wa Array ya NumPy
• Tafuta wa Array ya NumPy
• Tafuta wa Array ya NumPy
• Tafuta wa Array ya NumPy
• Uandikishaji wa NumPy
• Uandikishaji wa NumPy

机器学习

• 入门
• 平均中位数模式
• 标准差
• 百分位数
• 数据分布
• 正态数据分布
• 散点图
• 线性回归
• 多项式回归
• 多元回归
• 缩放
• 训练/测试
• 决策树

Python MySQL

• MySQL 入门
• MySQL Create Database
• MySQL Create Table
• MySQL Insert
• MySQL Select
• MySQL Where
• MySQL Order By
• MySQL Delete
• MySQL Drop Table
• MySQL Update
• MySQL Limit
• MySQL Join

Python MongoDB

• MongoDB 入门
• MongoDB 创建数据库
• MongoDB 创建集合
• MongoDB Insert
• MongoDB Find
• MongoDB Query
• MongoDB Sort
• MongoDB Delete
• MongoDB 删除集合
• MongoDB Update
• MongoDB Limit

Makala ya mifano ya Python

• Python 参考概览
• Python 内建函数
• Python 字符串方法
• Python 列表方法
• Python 字典方法
• Python 元组方法
• Python 集合方法
• Python 文件方法
• Python 关键字

模块参考手册

• 随机模块
• 请求模块

Python How To

• 删除列表重复项
• 反转字符串

Mfano wa Python

• Mfano wa Python
• Muafaka wa Python

选修课

课程推荐：

• Kiboxi ya CodeW3C.com

Python 集合（数组）

Python 编程语言中有四种集合数据类型：

• 列表（List）是一种有序和可更改的集合。允许重复的成员。
• 元组（Tuple）是一种有序且不可更改的集合。允许重复的成员。
• 集合（Set）是一个无序和无索引的集合。没有重复的成员。
• 词典（Dictionary）是一个无序，可变和有索引的集合。没有重复的成员。

It is useful to understand the properties of the type when choosing a collection type.

Choosing the correct type for a specific dataset may mean retaining meaning, and it may mean improving efficiency or security.

List

A list is an ordered and mutable collection. In Python, lists are written with square brackets.

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Create a list:

thislist = ["apple", "banana", "cherry"]
print(thislist)

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Access item

You can access list items by referencing the index number:

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Print the second item of the list:

thislist = ["apple", "banana", "cherry"]
print(thislist[1])

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Negative indices

Negative indices represent starting from the end, -1 represents the last item, -2 represents the second last item, and so on.

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Print the last item of the list:

thislist = ["apple", "banana", "cherry"]
print(thislist[-1])

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Index range

You can specify an index range by specifying the start and end of the range.

After specifying a range, the returned value will be a new list containing the specified items.

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Return the third, fourth, and fifth items:

thislist = ["apple", "banana", "cherry", "orange", "kiwi", "melon", "mango"]
print(thislist[2:5])

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Note:The search will start from index 2 (inclusive) to index 5 (exclusive).

Remember, the index of the first item is 0.

Range of negative indices

If you want to start searching from the end of the list, specify a negative index:

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This example will return items from index -4 (inclusive) to index -1 (exclusive):

thislist = ["apple", "banana", "cherry", "orange", "kiwi", "melon", "mango"]
print(thislist[-4:-1])

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Change item value

To change the value of a specific item, refer to the index number:

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Change the second item:

thislist = ["apple", "banana", "cherry"]
thislist[1] = "mango"
print(thislist)

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To traverse the list

You can use for Loop through list items:

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Print all items in the list one by one:

thislist = ["apple", "banana", "cherry"]
for x in thislist:
  print(x)

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You will learn Makikuu ya For ya Python Learn about for More about loops.

Check if item exists

To determine if a specified item exists in the list, use in Keyword:

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Check if 'apple' exists in the list:

thislist = ["apple", "banana", "cherry"]
if "apple" in thislist:
  print("Yes, 'apple' is in the fruits list")

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List length

To determine how many items are in the list, use len() Method:

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Print the number of items in the list:

thislist = ["apple", "banana", "cherry"]
print(len(thislist))

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Add item

To add an item to the end of the list, use append() Method:

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Kutumia: append() Method to append items:

thislist = ["apple", "banana", "cherry"]
thislist.append("orange")
print(thislist)

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To add an item at a specified index, use insert() Method:

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插入项目作为第二个位置：

thislist = ["apple", "banana", "cherry"]
thislist.insert(1, "orange")
print(thislist)

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删除项目

有几种方法可以从列表中删除项目：

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remove() 方法删除指定的项目：

thislist = ["apple", "banana", "cherry"]
thislist.remove("banana")
print(thislist)

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pop() 方法删除指定的索引（如果未指定索引，则删除最后一项）：

thislist = ["apple", "banana", "cherry"]
thislist.pop()
print(thislist)

Mfano wa kufungua

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del 关键字删除指定的索引：

thislist = ["apple", "banana", "cherry"]
del thislist[0]
print(thislist)

Mfano wa kufungua

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del 关键字也能完整地删除列表：

thislist = ["apple", "banana", "cherry"]
del thislist

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clear() 方法清空列表：

thislist = ["apple", "banana", "cherry"]
thislist.clear()
print(thislist)

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复制列表

您只能通过键入 list2 = list1 来复制列表，因为：list2 将只是对 list1 的引用，list1 中所做的更改也将自动在 list2 中进行。

有一些方法可以进行复制，一种方法是使用内置的 List 方法 copy()。

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Kutumia: copy() 方法来复制列表：

thislist = ["apple", "banana", "cherry"]
mylist = thislist.copy()
print(mylist)

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制作副本的另一种方法是使用内建的方法 list()。

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Kutumia: list() 方法复制列表：

thislist = ["apple", "banana", "cherry"]
mylist = list(thislist)
print(mylist)

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合并两个列表

在 Python 中，有几种方法可以连接或串联两个或多个列表。

最简单的方法之一是使用 + 运算符。

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合并两个列表：

list1 = ["a", "b" , "c"]
list2 = [1, 2, 3]
list3 = list1 + list2
print(list3)

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连接两个列表的另一种方法是将 list2 中的所有项一个接一个地追加到 list1 中：

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把 list2 追加到 list1 中：

list1 = ["a", "b" , "c"]
list2 = [1, 2, 3]
for x in list2:
  list1.append(x)
print(list1)

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或者，您可以使用 extend() 方法，其目的是将一个列表中的元素添加到另一列表中：

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使用 extend() 方法将 list2 添加到 list1 的末尾：

list1 = ["a", "b" , "c"]
list2 = [1, 2, 3]
list1.extend(list2)
print(list1)

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list() 构造函数

也可以使用 list() 构造函数创建一个新列表。

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Kutumia: list() Kumekua kina cha kuzengera orodha:

thislist = list(("apple", "banana", "cherry")) # Tafuta mabuni ya pili
print(thislist)

Mfano wa kufungua

Vifaa vya kipimo

Python ina kikomo cha vifaa ambavyo vinaweza kutumika kwenye kipimo

Kituagiza cha vifaa

Makala ya mifano ya Python

Mfano wa Python

Muafaka wa Python

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