147 lines
1.6 KiB
Markdown
147 lines
1.6 KiB
Markdown
### 条件语句
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- 正常写法
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```python
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a = 20
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b = 10
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if a==b:
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print("a == b")
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elif a < b:
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print("a < b")
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else:
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pring("a > b")
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```
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- 简写一行if
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```python
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a = 20
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b = 10
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if a > b: print("a > b")
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```
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- 简写一行if else
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```python
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a = 20
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b = 10
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print("A") if a > b else print("B")
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```
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- pass 语句，空if处理
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```python
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a = 66
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b = 200
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if b > a:
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pass
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```
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### and or
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```python
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a = 200
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b = 66
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c = 500
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if a > b and c > a:
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print("Both conditions are True")
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a = 200
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b = 66
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c = 500
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if a > b or a > c:
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print("At least one of the conditions is True")
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```
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### while 循环
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- break 终止循环
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- continue 开始下一次循环
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```python
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i = 1
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while i < 7:
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print(i)
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if i == 3:
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break
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i += 1
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```
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```python
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i = 0
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while i < 7:
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i += 1
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if i == 3:
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continue
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print(i)
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```
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- else语句，条件不成立，执行else语句
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```python
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i = 1
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while i < 6:
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print(i)
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i += 1
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else:
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print("i is no longer less than 6")
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```
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### for 循环
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- break
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- continue
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```python
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fruits = ["apple", "banana", "cherry"]
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for x in fruits:
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if x == "banana":
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continue
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print(x)
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fruits = ["apple", "banana", "cherry"]
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for x in fruits:
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print(x)
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if x == "banana":
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break
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```
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- range() 函数：返回一个数字序列，默认情况下从 0 开始，并递增 1（默认地），并以指定的数字结束
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```python
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for x in range(10):
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print(x)
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for x in range(3, 10):
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print(x)
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for x in range(3, 50, 6):
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print(x)
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```
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- else for循环不满足条件时执行else语句
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```python
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for x in range(10):
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print(x)
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else:
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print("Finally finished!")
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```
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- pass语句
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```python
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for x in [0, 1, 2]:
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pass
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```
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