pythotn条件分支与循环详解

if boolean_value:
		子代码模块1

>>> if True:
	print("hello world")

hello world

hello world
>>> if 5>2:
	print("xxxxx")

xxxxx
>>> if 2>5:
	print("ok")

>>> 

if boolean_value:
	子代码模块1
else:
	子代码模块2

>>> if False:
		print("ok")
	else:
		print("no")

no

if boolean_value1:
	子代码模块1
elif boolean_value2:
	子代码模块2
else:
	子代码模块3

#三酷猫钓鱼记录查找
fish_record = "鲫鱼5条、鲤鱼8条、鲢鱼7条、草鱼2条、黑鱼6条、乌龟1只"
print(len(fish_record))

if fish_record[0:2]=="乌龟":
    print("是乌龟吗？，是"+fish_record[0:2])
    
elif fish_record[5:7]=="乌龟":
    print("是乌龟吗？，是"+fish_record[5:7])
    
elif fish_record[10:12]=="乌龟":
    print("是乌龟吗？，是"+fish_record[10:12])
    
elif fish_record[15:17]=="乌龟":
    print("是乌龟吗？，是"+fish_record[15:17])
    
elif fish_record[20:22]=="乌龟":
    print("是乌龟吗？，是"+fish_record[20:22])
    
elif fish_record[25:27]!="乌龟":
    if int(fish_record[27])%2 == 0:
        print("找到乌龟了，是%d只，偶数"%(int(fish_record[27])))
    else:
        print("找到乌龟了，是%d只，奇数"%(int(fish_record[27])))

pwd = ''  # 注：这个''代表空字符串
while pwd != '520666':
    pwd = input('请输入银行卡密码：')
print('卡内还有999999999999元~')

while i<2:
	while i<j:
		print("%d,"%((i+1)*j))
		i -= 1
	i += 1

# 获取用户输入的任意数，判断其是否是质数?
while True:
    n = int(input('请输入数字：'))
    if n == 0:
        print('%d不是质数，请重新输入！'%n)
    elif n % 2 == 1:
        print('%d是质数。'%n)
        break
    else:
        continue