python 小练习1

练习1：
#!/usr/bin/python3
# 根据输入的行数，绘制一个矩形

while True:
    nums = int(input("请输入矩形的所占行数(大于2小于20)："))
    if nums < 2 or nums > 20:
        print("输入有误，请重新输入")
        continue
    else:
        break

star = '* ' * nums

print(star)

for i in range(nums):
    blank = '  ' * (nums - 2)
    print('* ' + blank + '*')

print(star)

练习2：
#!/usr/bin/python3
# 判断是否为回文

print("判断是否是回文：")

while True:
    string = input("请输入一个字符串：")
    length = len(string)

    if length < 2:
        print("The length of input string should be longer than 2: length:%d" % (length,))
        continue
    else:
        break

flag = True
for i in range(length // 2):
    if string[i] != string[length - 1 - i]:
        flag = False
        break

if flag:
    print("input: "%s " is huiwen" % (string,))
else:
    print("input: "%s " is not huiwen" % (string,))

练习3：
#!/usr/bin/python3
# 输入一个整数，小球从此高度落下，每次反弹的距离是原始高度的一半，回弹高度小于0.01米时，
# 结束，求小球回弹的次数，和一共经过的距离

while True:
    height = int(input("请输入小球落下的高度(大于1米)："))
    if height < 1:
        print("输入有误，请重新输入")
        continue
    else:
        break

orgin = float(height)

count = 0
distance = 0

while orgin / 2> 0.01:
    count += 1
    # 每次下落时距离应该是落下的高度和回弹的高度值之和
    distance += orgin + orgin / 2;
    orgin /= 2

# 应该加上最后依次落下的高度
distance += orgin
print("从%d落下后，一共反弹%d次，一共经过的距离%f" % (height, count, distance))

练习4：
#!/usr/bin/python3
# 随机产生一注双色球号码：7个红球(范围1~33，不能重复)和1个篮球(1-16)
import random

reds = []

for i in range(7):
    ball = str(random.randint(1, 33))
    while ball in reds:
        ball = str(random.randint(1, 33))
    else:
        reds.append(ball)

red = " ".join(reds)
blue = str(random.randint(1, 16))

rcolor = "31"
bcolor = "34"

print("The random number is (33[%s;40m%s33[0m  33[%s;40m%s33[0m)"
      % (rcolor, red, bcolor, blue))

执行结果：

练习5：
#!/usr/bin/bash
# 产生100以内10个不同的随机数放入list1
# list1的每个值进行平方放入list2
# list1中50以内的数值放入list3
# list1中每个偶数进行平方加1，放入list4
import random

list1 = []
for i in range(10):
    val = random.randint(1, 100)
    while val in list1:
        val = random.randint(1, 100)
    else:
        list1.append(val)

print("list1:" + str(list1))

list2 = [item ** 2 for item in list1]
list3 = [item for item in list1 if item < 50]
list4 = [item ** 2 + 1 for item in list1 if item % 2 == 0]


print("list1:" + str(list1))
print("list2:" + str(list2))
print("list3:" + str(list3))
print("list4:" + str(list4))