Python Exercise 2

Question:
1. Write out several branch structures in Python and explain their execution process;

(1) if:
If expression: #条件
Statement #输出


(2) If...else ...
If expression: #条件

Statement #输出
else: #其他条件
Statement #其他输出

(3) If...elif...else ...
If expression: #条件1
Statement #输出1

Elif expression: #条件2

Statement #输出2

Else

Statement #其他输出

2. Write out several loop structures in Python and explain their execution process;

(1) For loop
For I in Range (m.n,x):
The Loop statement #条件

Statement #输出


(2) While loop
While expression (or True,false):
The Loop statement #条件
Statement #输出


(2) while ... else .....
While expression:
Loop Statement #条件1

Statement #输出1

Else

Statement #输出2

3. Do you support switch statements in Python?
If supported, write out the statement format;
If not, say how python can achieve the same functionality;

In Python does not support switch statements, if you want to achieve the effect of switch, is to use if...elif...elif...else ... Statement

Programming Exercises:

1. The user enters a number to determine whether it is prime;

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2. Write a Python script to determine if the variable name entered by the user is legal?
(The first letter or underscore, the others are numbers, letters or underscores)

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Python Exercise 2