条件判断

条件判断 

if...elseif....else..

# condiction_1
# condiction_2
# condiction_3
if condiction_1:
    statement_block_1
elif condiction_2:
    statement_block_2
else:
    statement_block_3

condiction_1为True时，输出为 statement_block_1

条件判断语句结束

condiction_1为True时，输出为 statement_block_1

条件判断语句结束

condiction_1，condiction_1为false时，到else 代码块，输出为 statement_block_1

条件判断语句结束

条件语句的嵌套：

# condiction_1
# condiction_2
# condiction_3
if condiction_1:
    if condiction_2:
        statement_block_2
    else:
        statement_block_3
else:
    statement_block_1

condiction_1为True，进入下一个条件判断。

condiction_2为True，输出为statement_block_2，否者输出为statement_block_3

condiction_1为false,输出为

statement_block_1