控制流:一系列按顺序执行的指令
for(元素出现顺序迭代)
f = [1,3,6]
for i in f:
print(i)
>>>
1
3
6
##字典遍历 键找值
d = {"a":1,"b":2}
for k in d:
print(k,d[k])
>>>
a 1
b 2
##键值都返回
for k,v in d.item():
print(k,v)
>>>
a 1
b 2
if
if int(input("Enter an inger : ")) == 1:
print("yeah!")
>>>Enter an inger : 1
>>>yeah!
>>>Enter an inger : 2
>>>不符合就不操作
if int(input("Enter an inger : ")) == 1:
print("yeah!")
else:
print("Oops!")
>>>Enter an inger : 2
>>>Oops!
if i<10:
print("i<10")
elif i<20:
print("10<=i<=20")
elif:
print(">=20")
while
a = 0
while a < 3:
print(a)
a+=1
>>>
0
1
2
break
f = [1,3,6]
for i in f:
if i>5:
break
print(i)
>>>
1
3
continue
f = [1,3,6]
for i in f:
if i == 3:
continue
print(i)
range
range(5)
range(0,5)
list(range(5))
list(range(1,5,2))
##不到5
pass
class MyEmptyClass:
pass
while False:
pass
##什么都不做 占位
https://docs.python.org/3/tutorial/controlflow.html 2. https://python.swaroopch.com/control_flow.html