print(keyword.kwlist) # ['False', 'None', 'True', 'and', 'as', 'assert', 'break', 'class', 'continue', 'def', 'del', 'elif', 'else', 'except', 'finally', 'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda', 'nonlocal', 'not', 'or', 'pass', ...
while expression: statement(s) statement(s) break:就像在C语言中,打破了最小封闭for或while循环 continue :跳出本次循环 pass:空语句,是为了保持程序结构的完整性。pass 不做任何事情,一般用做占位语句。 函数 定义函数 def functionname( parameters ): "函数_文档字符串" function_suite return [expression] ...
if else 逻辑值包含了两个值 Ture: 表示非空的量(string,tuple,list,set,dictionary),所有非零数。 Flase: 表示0,None,空的量。 elif语句 if expression1: statement1(s) elif expression2: statement2(s) elif expression3: statement3(s) else: statement4(s) 将字符串进行大小写转换 a='abc' a.lowe...
Elif- 否则如果: 用于多条件判断中，位于if与else之间。List- 列表: 用于存储多个数据项的集合。Dictio...
ifcondition_1: statement_block_1elifcondition_2: statement_block_2else: statement_block_3 循环语句 Python 中的循环语句有 for 和 while。 break 语句可以跳出 for 和 while 的循环体。 continue 语句跳过当前循环继续进行下一轮循环。 while循环
Typehelp()forinteractive help,orhelp(object)forhelp about object.>>>help()Welcome to Python3.6's help utility!Ifthisis your first time using Python,you should definitely check out the tutorial on the Internet at https://docs.python.org/3.6/tutorial/.Enter the nameofany module,keyword,or top...
Introduction to the if Statement We’ll start by looking at the most basic type of if statement. In its simplest form, it looks like this: Python if <expr>: <statement> In the form shown above: <expr> is an expression evaluated in a Boolean context, as discussed in the section on...
Remove Dictionary Items We can use thedelstatement to remove an element from a dictionary. For example, country_capitals = {"Germany":"Berlin","Canada":"Ottawa", } # delete item having "Germany" keydelcountry_capitals["Germany"] print(country_capitals) ...
The dictionary in membership expression allows us to query the existence of a key and branch on the result with a Python if statement (as with the for, be sure to press Enter twice to run the if interactively here): >>> 'f' in D False >>> if not 'f' in D: print('missing') ...
Python当中的判断语句非常简单,并且Python不支持switch,所以即使是多个条件,我们也只能罗列if-else。 # Let's just make a variable some_var = 5 # Here is an if statement. Indentation is significant in Python! # Convention is to use four spaces, not tabs. ...