# 10.流程控制

### 1. 条件语句 if/else

```python
if condition:
    #####
elif condition:
    #####
else: 
    ##### 
```

在 Python 中，没有 switch/case 语句\
​

### 2. 循环语句 while/for

```python
# while 语句

while condition:
    #### condition 满足执行
else:
    #### 循环结束执行
    
      
# for 语句

for <variable> in <sequence>:
    #### 
else:
    #### 循环结束执行

```

### 3. Range函数

**Python** 内置 range 函数可以创建一组数列(不是list)\
​

```python
range1 = range(5)           # 0,1,2,3,4

range2 = range(1,5)         # 1,2,3,4

range3 = range(1,10,2)      # 1,3,5,7,9         2 为 步长


li = list(range(1,11))      # 使用range创建 list
```

​

### 4. break/continue

break 语句用于跳出循环体\
​

continue 语句用于结束当前这次循环，继续下一次循环\
​

跳出循环体之后，else 语句将不会执行

### 5. pass

Python 的 **pass** 是空语句，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

```python
for letter in 'Runoob': 
   if letter == 'o':
      pass
      print ('执行 pass 块')
   print ('当前字母 :', letter)
 
print ("Good bye!")


'''
当前字母 : R
当前字母 : u
当前字母 : n
执行 pass 块
当前字母 : o
执行 pass 块
当前字母 : o
当前字母 : b
Good bye!
'''
```


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