Yes No # --- -- if 'foo' in ['foo', 'bar', 'baz']: # x print('Outer condition is true') # x if 10 > 20: # x print('Inner condition 1') # x print('Between inner conditions') # x if 10 < 20: # x print('Inner condition 2') # x print('End of outer condition'...
print('x is positive') 1. 2. if 之后的布尔表达式被称作条件(condition)。 如果它为真,则缩进的语句会被执行。 如果不是,则什么也不会发生。 if 语句和函数定义有相同的结构:一个语句头跟着一个缩进的语句体。 类似的语句被称作复合语句(compound statements)。 语句体中可出现的语句数目没有限制,但是至少...
这样词法分析过程中,缩进的词法分析过程就完了,在语法分析中,Indent是透明的,例如: compound_stmt : IF compound_condition (suite)+ elif_clause* else_clause? | assignment ; suite : INDENT (compound_stmt)+ (DEDENT | EOF) ; 上面的语法中,INDENT和DEDENT就跟括号的处理没什么区别,只不过DEDENT可选,主要...
>>>while condition: >>> block 1. 2. 8.3 用户输入循环 >>>text = "" >>>while text != "quit": >>> text = raw_input("Please enter a chemical formula (or 'quit' to exit):") >>> if text == "quit": >>> print"...exiting program" >>> elif text == "H20": >>> print"...
9.Python Tkinter compound 10.Python Tkinter Entry和Text 11.Python Tkinter Radiobutton和Checkbutton 12.Python Tkinter Listbox和Combobox 13.Python Tkinter Spinbox 14.Python Tkinter Scale和LabeledScale 15.Python Tkinter LabelFrame 16.Python Tkinter Panedwindow ...
They constitute the block that would be executed if the condition were true. But it is false, so all the statements in the block are skipped. After the end of the compound if statement has been reached (whether the statements in the block on lines 2 to 5 are executed or not), ...
"""WHILE statement @see: https://docs.python.org/3/tutorial/controlflow.html @see: https://docs.python.org/3/reference/compound_stmts.html#the-while-statement The while loop executes as long as the condition remains true. In Python, like in C, any non-zero integer value is true; zero...
9.Python Tkinter compound 10.Python Tkinter Entry和Text 11.Python Tkinter Radiobutton和Checkbutton 12.Python Tkinter Listbox和Combobox 13.Python Tkinter Spinbox 14.Python Tkinter Scale和LabeledScale 15.Python Tkinter LabelFrame 16.Python Tkinter Panedwindow ...
If an asserted condition becomes false, then you immediately know that you have a bug. As an example, say that you have the following Circle class: Python circle.py import math class Circle: def __init__(self, radius): if radius < 0: raise ValueError("positive radius expected") self...
循环结构中的 else 会在循环没被 break 的时候执行 try 语句中的 else 会在没遇到异常时执行 END 参考资料: https://docs.python.org/3.8/tutorial/controlflow.html https://docs.python.org/3.8/reference/compound_stmts.html 以上内容如有错误,欢迎指出!