Python | 条件判断if与循环for/while

if condition_1:
    statement_block_1
elif condition_2:
    statement_block_2
else:
    statement_block_3	

1. >
2. <
3. >=
4. <=
5. !=
6. ==

7. and
8. or
9. not

for遍历

for  in :
    
else:
    

while循环，如果条件为真，则执行

while 判断条件(condition)：
    执行语句(statements)……
else:
    其他执行条件 
for使用 
>>> d2={'name': 'tom', 'sex': 'man', 'age': '18', 'interest': 'reading'}
>>> d3={}
>>> for k,v in d2.items():
        new_v=v.upper()
        new_k=k.upper()
        d3[new_k]=new_v
>>> print(d3)
{'NAME': 'TOM', 'SEX': 'MAN', 'AGE': '18', 'INTEREST': 'READING'}

>>> i=0
>>> sum=0
>>> for i in range(1,101):
...     sum+=i
...
>>> sum
5050
 
while使用 
>>> sum=0
>>> i=0
>>> while i<=100:
...     sum=sum+i
...     i=i+1
...
>>> sum
5050

>>> sum=0
>>> i=0
>>> while i<5:
...     sum=sum+i
...     i=i+1
...     print(sum)
... else:
...     print('i=5')
...
0
1
3
6
10
i=5