提交 c04f1858 编写于 作者: W wizardforcel

2020-06-12 16:58:40

上级 121f5365
......@@ -6,7 +6,9 @@
Python 中有 35 个关键字 - 下面列出了它们的用法。
| **和** | A **logical AND** operator. Return `True` if both statements are `True`.
`and`
A **logical AND** operator. Return `True` if both statements are `True`.
```java
x = (5 > 3 and 5 < 10)
......@@ -14,8 +16,10 @@ Python 中有 35 个关键字 - 下面列出了它们的用法。
```
|
| **或** | A **logical OR** operator. Returns `True` if either of two statements is true. If both statements are false, the returns `False`.
`or`
逻辑或运算符。 如果两个语句中的任何一个为`True`,则返回`True`。 如果两个语句都为假,则返回`False`
```java
x = (5 > 3 or 5 > 10)
......@@ -23,8 +27,10 @@ Python 中有 35 个关键字 - 下面列出了它们的用法。
```
|
| **作为** | It is used to create an alias.
`as`
它用于创建别名。
```java
import calendar as c
......@@ -32,8 +38,10 @@ Python 中有 35 个关键字 - 下面列出了它们的用法。
```
|
| **断言** | It can be used for debugging the code. It tests a condition and returns `True` , if not, the program will raise an AssertionError.
`assert`
它可以用于调试代码。 它会测试条件并返回`True`,否则产生`AssertionError`
```java
x = "hello"
......@@ -42,15 +50,19 @@ Python 中有 35 个关键字 - 下面列出了它们的用法。
```
|
| **异步** | It is used to declare a function as a coroutine, much like what the `@asyncio.coroutine` decorator does.
`async`
它用来声明一个函数为协程,就像`@asyncio.coroutine`装饰器所做的一样。
```java
async def ping_server(ip):
```
|
| **等待** | It is used to call `async` coroutine.
`await`
它用于调用`async`协程。
```java
async def ping_local():
......@@ -58,8 +70,10 @@ async def ping_server(ip):
```
|
| **类** | It is used to create a class.
`class`
它用于创建一个类。
```java
class User:
......@@ -68,8 +82,10 @@ async def ping_server(ip):
```
|
| **def** | It is used to create or define a function.
`def`
它用于创建或定义函数。
```java
def my_function():
......@@ -79,8 +95,10 @@ async def ping_server(ip):
```
|
| 的 | It is used to delete objects. In Python everything is an object, so the `del` keyword can also be used to delete variables, [lists](https://howtodoinjava.com/python/python-lists/), or parts of a list, etc.
`del`
它用于删除对象。 在 Python 中,所有事物都是对象,因此`del`关键字也可以用于删除变量,[列表](https://howtodoinjava.com/python/python-lists/)或列表的一部分,等等。
```java
x = "hello"
......@@ -89,8 +107,10 @@ async def ping_server(ip):
```
|
| 如果为 | It is used to create conditional statements that allows us to execute a block of code only if a condition is `True`.
`if`
它用于创建条件语句,该条件语句仅在条件为`True`时才允许我们执行代码块。
```java
x = 5
......@@ -100,9 +120,10 @@ async def ping_server(ip):
```
|
| **elif** | It is used in conditional statements and is short for `else if`.
`elif`
它用于条件语句中,是`else if`的缩写。
```java
i = 5
......@@ -115,8 +136,10 @@ async def ping_server(ip):
```
|
| **其他** | It decides what to do if the condition is `False` in `if..else` statement.
`else`
它决定如果`if..else`语句中的条件为`False`时该怎么办。
```java
i = 5
......@@ -142,9 +165,15 @@ async def ping_server(ip):
```
|
| **试试** | 如果它包含任何错误,它将定义一个测试代码块。 |
| 除了 | It defines a block of code to run if the try block raises an error.
`try`
如果它包含任何错误,它将定义一个测试代码块。
`except`
如果`try`块引发错误,它将定义要运行的代码块。
```java
try:
......@@ -154,8 +183,10 @@ async def ping_server(ip):
```
|
| **终于** | It defines a code block which will be executed no matter if the try block raises an error or not.
`finally`
它定义了一个代码块,无论`try`块是否引发错误,该代码块都将执行。
```java
try:
......@@ -167,8 +198,10 @@ async def ping_server(ip):
```
|
| **加注** | It is used to raise an exception, manually.
`raise`
它用于手动引发异常。
```java
x = "hello"
......@@ -178,10 +211,19 @@ async def ping_server(ip):
```
|
| **错误** | 它是一个布尔值,与 0 相同。 |
| **正确** | 它是一个布尔值,与 1 相同。 |
| 的 | It is used to create a for loop. A for loop can be used to iterate through a sequence, like a list, tuple, etc.
`False`
它是一个布尔值,与 0 相同。
`True`
它是一个布尔值,与 1 相同。
`for`
它用于创建`for`循环。 `for`循环可用于遍历序列(如列表,元组等)。
```java
for x in range(1, 9):
......@@ -189,8 +231,10 @@ async def ping_server(ip):
```
|
| **而** | It is used to create a while loop. The loop continues until the conditional statement is false.
`while`
它用于创建`while`循环。 循环继续进行,直到条件语句为假。
```java
x = 0
......@@ -201,8 +245,10 @@ async def ping_server(ip):
```
|
| **中断** | It is used to break out a for loop, or a while loop.
`break`
它用于中断`for`循环或`while`循环。
```java
i = 1
......@@ -215,8 +261,10 @@ async def ping_server(ip):
```
|
| **继续** | It is used to end the current iteration in a for loop (or a while loop), and continues to the next iteration.
`continue`
它用于在`for`循环(或`while`循环)中结束当前迭代,并继续进行下一个迭代。
```java
for i in range(9):
......@@ -226,22 +274,28 @@ async def ping_server(ip):
```
|
| 进口 | It is used to import modules.
`import`
它用于导入模块。
```java
import datetime
```
|
| 中的 | It is used to import only a specified section from a module.
`from`
它仅用于从模块中导入指定的节。
```java
from datetime import time
```
|
| **全局** | It is used to create global variables from a no-global scope, e.g. inside a function.
`global`
它用于从非全局范围创建全局变量,例如在函数内部。
```java
def myfunction():
......@@ -250,9 +304,12 @@ from datetime import time
```
|
| 中的 | 1\. It is used to check if a value is present in a sequence (list, range, string etc.).
2\. It is also used to iterate through a sequence in a `for` loop.
`in`
1\. 它用于检查序列(列表,范围,字符串等)中是否存在值。
2\. 它也用于在`for`循环中遍历序列。
```java
fruits = ["apple", "banana", "cherry"]
......@@ -265,8 +322,10 @@ from datetime import time
```
|
| **是** | It is used to test if two variables refer to the same object.
`is`
它用于测试两个变量是否引用同一对象。
```java
a = ["apple", "banana", "cherry"]
......@@ -278,8 +337,10 @@ from datetime import time
```
|
| **lambda** | It is used to create small anonymous functions. They can take any number of arguments, but can only have one expression.
`lambda`
它用于创建小的匿名函数。 它们可以接受任意数量的参数,但只能有一个表达式。
```java
x = lambda a, b, c : a + b + c
......@@ -288,9 +349,12 @@ from datetime import time
```
|
| **无** | It is used to define a `null` value, or no value at all. None is not the same as 0, False, or an empty string.
None is a datatype of its own (*NoneType*) and only None can be None.
`None`
它用于定义一个“空”值,或者根本没有值。 `None`与 0,`False`或空字符串不同。
`None`是它自己的数据类型(`NoneType`),并且只有`None`可以是`None`
```java
x = None
......@@ -302,8 +366,10 @@ None is a datatype of its own (*NoneType*) and only None can be None.
```
|
| **非本地** | It is used to declare that a variable is not local. It is used to work with variables inside nested functions, where the variable should not belong to the inner function.
`nonlocal`
它用于声明变量不是局部变量。 它用于在嵌套函数内部使用变量,其中变量不应属于内部函数。
```java
def myfunc1():
......@@ -318,8 +384,10 @@ None is a datatype of its own (*NoneType*) and only None can be None.
```
|
| **不是** | It is a logical operator and reverses the value of True or False.
`not`
它是一个逻辑运算符,并反转`True``False`的值。
```java
x = False
......@@ -328,26 +396,35 @@ None is a datatype of its own (*NoneType*) and only None can be None.
```
|
| **通过** | It is used as a placeholder for future code. When the pass statement is executed, nothing happens, but you avoid getting an error when an empty code is not allowed.循环,函数定义,类定义或 if 语句中不允许使用空代码。
`pass`
它用作将来代码的占位符。 当执行`pass`语句时,什么也不会发生,但是当不允许使用空代码时,可以避免出现错误。循环,函数定义,类定义或`if`语句中不允许使用空代码。
```java
for x in [0, 1, 2]:
pass
```
|
| **返回** | It is to exit a function and return a value.
`return`
它是退出一个函数并返回一个值。
```java
def myfunction():
return 3+3
```
|
| **与** | 用于简化异常处理 |
| **产量** | 要结束一个函数,返回一个生成器 |
`as`
用于简化异常处理
`yield`
要结束一个函数,返回一个生成器
学习愉快!
参考: [W3 学校](https://www.w3schools.com/python/python_ref_keywords.asp)
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参考: [W3School](https://www.w3schools.com/python/python_ref_keywords.asp)
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