python--常见笔试题

一、冒泡排序

'''冒泡排序'''
# coding:utf-8
list = [1, 13, 5, 35, 6, 9, 10]
s = range(len(list))[::-1]
print(s)
for i in s:
    for j in range(i):
        if list[j] > list[j +1 ]:
            list[j], list[j + 1] = list[j + 1], list[j]
print(list)

def bubbleSort(nums):
    for i in range(len(nums)-1):    # 这个循环负责设置冒泡排序进行的次数
        for j in range(len(nums)-i-1):  # ｊ为列表下标
            if nums[j] > nums[j+1]:
                nums[j], nums[j+1] = nums[j+1], nums[j]
    return nums

nums = [5,2,45,6,8,2,1]

print bubbleSort(nums)

二、字符串切片

# 字符串切片，取a中的abcd
a = "apbocidu"

# 方法一：
b = a[::2]
print(b)

# 方法二：
c = []
for i in range(len(a)):
    if i % 2 == 0:
        c.append(a[i])
print("".join(c))

 三、字符串切割

# 字符串切割，"hello_world_hehe"转换成"hello","world","hehe"
a = "hello_world_hehe"
b = a.split("_")
print(b)

 四、字符串合并

# 字符串合并，["a","b","c","d"]合并成"abcd"
a = ['a', 'b', 'c', 'd']
b = "".join(a)      # join连接字符串
print(b)

五、列表生成式

# 列表生成式
a = [x*((-1)**(x+1)) for x in range(1, 101)]
print(a)
print(sum(a))

 六、斐波那契数列（递归）

# 递归(菲波那切数列)
a = 0
b = 1
while b < 100:
    print(b, end=',')
    a, b =b, a+b