30 个 Python 代码小片段

lis = [56,12,1,8,354,10,100,34,56,7,23,456,234,-58]

def sortport():
    for i in range(len(lis)-1):
        for j in range(len(lis)-1-i):
            if lis[j] > lis[j+1]:
                lis[j],lis[j+1] = lis[j+1],lis[j]
    return lis

def power(x, n):
    s = 1
    while n > 0:
        n = n - 1
        s = s * x
    return s

def calc(*numbers):
  sum = 0
  for n in numbers:
    sum = sum + n * n
  return sum

def fac():
  num = int(input("请输入一个数字: "))
  factorial = 1

# 查看数字是负数，0 或 正数
  if num < 0:
    print("抱歉，负数没有阶乘")
  elif num == 0:
    print("0 的阶乘为 1")
  else:
    for i in range(1, num + 1):
      factorial = factorial * i
    print("%d 的阶乘为 %d" % (num, factorial))

def factorial(n):
  result = n
  for i in range(1, n):
    result *= i
  return result

def fact(n):
    if n==1:
        return 1
    return n * fact(n - 1)

[d for d in os.listdir('.')]

L = ['Hello', 'World', 'IBM', 'Apple']
[s.lower() for s in L]

def print_dir():
  filepath = input("请输入一个路径：")
  if filepath == "":
    print("请输入正确的路径")
  else:
    for i in os.listdir(filepath):       #获取目录中的文件及子目录列表
      print(os.path.join(filepath,i))  #把路径组合起来

print(print_dir())

def show_dir(filepath):
  for i in os.listdir(filepath):
    path = (os.path.join(filepath, i))
    print(path)
    if os.path.isdir(path):      #isdir()判断是否是目录
      show_dir(path)             #如果是目录，使用递归方法

filepath = "C:\Program Files\Internet Explorer"
show_dir(filepath)

def print_dir(filepath):
  for i in os.listdir(filepath):
    path = os.path.join(filepath, i)
    if os.path.isdir(path):
      print_dir(path)
    if path.endswith(".html"):
      print(path)

filepath = "E:\PycharmProjects"
print_dir(filepath)

dict1 = {'A':'a', 'B':'b', 'C':'c'}
dict2 = {y:x for x,y in dict1.items()}

for i in range(1, 10):
    for j in range(1, i+1):
        # print('{}x{}={}\t'.format(j, i, i*j), end='')
        print('%d x %d = %d \t'%(i, j, i*j), end='')
    print()

num = ["harden","lampard",3,34,45,56,76,87,78,45,3,3,3,87686,98,76]
# print(num.count(3))
# print(num.index(3))
for i in range(num.count(3)):     #获取3出现的次数
    ele_index = num.index(3)      #获取首次3出现的坐标
    num[ele_index]="3a"           #修改3为3
    print(num)

L = ["James","Meng","Xin"]
for i in L:
    print("Hello,%s" % i)

list1 = [2, 3, 8, 4, 9, 5, 6]
list2 = [5, 6, 10, 17, 11, 2]

list3 = list1 + list2
print(list3)                # 不去重只进行两个列表的组合
print(set(list3))           # 去重,类型为set需要转换成list
print(list(set(list3)))

import random
list1=[]
for i in range(65,91):
    list1.append(chr(i))     #通过for循环遍历asii追加到空列表中
for j in range(97,123):
    list1.append(chr(j))
for k in range(48,58):
    list1.append(chr(k))
ma = random.sample(list1,6)
print(ma)                    #获取到的为列表       
ma = ''.join(ma)             #将列表转化为字符串
print(ma)

import random,string
str1 = "0123456789"
str2 = string.ascii_letters     # string.ascii_letters 包含所有字母（大写或小写）的字符串
str3 = str1+str2
ma1 = random.sample(str3,6)     #多个字符中选取特定数量的字符
ma1 = ''.join(ma1)              #使用join拼接转换为字符串
print(ma1)                      #通过引入string模块和random模块使用现有的方法

num = float(input('请输入一个数字：'))
num_sqrt = num ** 0.5
print(' %0.2f 的平方根为 %0.2f'%(num ,num_sqrt))

def is_number(s):
    try:
        float(s)
        return True
    except ValueError:
        pass
 
    try:
        import unicodedata
        unicodedata.numeric(s)
        return True
    except (TypeError, ValueError):
        pass
 
    return False

print(chri.isdigit())       #检测字符串是否只由数字组成
print(chri.isnumeric())     #检测字符串是否只由数字组成，这种方法是只针对unicode对象

num = int(input("输入一个数字: "))
if (num % 2) == 0:
   print("{0} 是偶数".format(num))
else:
   print("{0} 是奇数".format(num))

while True:
    try:
        num = int(input('输入一个整数：'))    #判断输入是否为整数
    except ValueError:                      #不是纯数字需要重新输入
        print("输入的不是整数！")
        continue
    if num % 2 == 0:
        print('偶数')
    else:
        print('奇数')
    break

year = int(input("输入一个年份: "))
if (year % 4) == 0:
   if (year % 100) == 0:
       if (year % 400) == 0:
           print("{0} 是闰年".format(year))   # 整百年能被400整除的是闰年
       else:
           print("{0} 不是闰年".format(year))
   else:
       print("{0} 是闰年".format(year))       # 非整百年能被4整除的为闰年
else:
   print("{0} 不是闰年".format(year))

year = int(input("请输入一个年份："))
if (year % 4) == 0 and (year % 100) != 0 or (year % 400) == 0:
    print("{0}是闰年".format(year))
else:
    print("{0}不是闰年".format(year))

import calendar

year = int(input("请输入年份："))
check_year=calendar.isleap(year)
if check_year == True:
    print ("%d是闰年"% year)
else:
    print ("%d是平年"% year)

N = int(input('输入需要对比大小数字的个数：'))
print("请输入需要对比的数字：")
num = []
for i in range(1,N+1):
    temp = int(input('输入第 %d 个数字:' % i))
    num.append (temp)

print('您输入的数字为：',num)
print('最大值为：',max(num))

N = int(input('输入需要对比大小数字的个数：\n'))

num = [ int(input('请输入第 %d 个对比数字: \n'%i))for i in range(1,N+1)]

print('您输入的数字为:',num)
print('最大值为: ',max(num))

# 判断输入的值是否合法
if nterms <= 0:
  print("请输入一个正整数。")
elif nterms == 1:
  print("斐波那契数列：")
  print(n1)
else:
  print("斐波那契数列：")
  print(n1, ",", n2, end=" , ")
  while count < nterms:
    nth = n1 + n2
    print(n1+n2, end=" , ")
    # 更新值
    n1 = n2
    n2 = nth
    count += 1

# 获取输入十进制数
dec = int(input("输入数字："))

print("十进制数为：", dec)
print("转换为二进制为：", bin(dec))
print("转换为八进制为：", oct(dec))
print("转换为十六进制为：", hex(dec))

def hcf(x, y):
  """该函数返回两个数的最大公约数"""

  # 获取最小值
  if x > y:
    smaller = y
  else:
    smaller = x

  for i in range(1, smaller + 1):
    if ((x % i == 0) and (y % i == 0)):
      hcf = i

  return hcf

# 用户输入两个数字
num1 = int(input("输入第一个数字: "))
num2 = int(input("输入第二个数字: "))

print(num1, "和", num2, "的最大公约数为", hcf(num1, num2))

# 定义函数
def lcm(x, y):
 
   #  获取最大的数
   if x > y:
       greater = x
   else:
       greater = y
 
   while(True):
       if((greater % x == 0) and (greater % y == 0)):
           lcm = greater
           break
       greater += 1
 
   return lcm
  
# 获取用户输入
num1 = int(input("输入第一个数字: "))
num2 = int(input("输入第二个数字: "))
 
print( num1,"和", num2,"的最小公倍数为", lcm(num1, num2))

# 定义函数
def add(x, y):
    """相加"""
    return x + y

def subtract(x, y):
    """相减"""
    return x - y

def multiply(x, y):
    """相乘"""
    return x * y

def divide(x, y):
    """相除"""
    return x / y

# 用户输入
print("选择运算：")
print("1、相加")
print("2、相减")
print("3、相乘")
print("4、相除")

choice = input("输入你的选择(1/2/3/4):")

num1 = int(input("输入第一个数字: "))
num2 = int(input("输入第二个数字: "))

if choice == '1':
    print(num1, "+", num2, "=", add(num1, num2))

elif choice == '2':
    print(num1, "-", num2, "=", subtract(num1, num2))

elif choice == '3':
    print(num1, "*", num2, "=", multiply(num1, num2))

elif choice == '4':
    if num2 != 0:
        print(num1, "/", num2, "=", divide(num1, num2))
    else:
        print("分母不能为0")
else:
    print("非法输入")

# 引入日历模块
import calendar

# 输入指定年月
yy = int(input("输入年份: "))
mm = int(input("输入月份: "))

# 显示日历
print(calendar.month(yy, mm))

# 写文件
with open("test.txt", "wt") as out_file:
    out_file.write("该文本会写入到文件中\n看到我了吧！")

# Read a file
with open("test.txt", "rt") as in_file:
    text = in_file.read()

print(text)

# 测试实例一
print("测试实例一")
str = "runoob.com"
print(str.isalnum()) # 判断所有字符都是数字或者字母
print(str.isalpha()) # 判断所有字符都是字母
print(str.isdigit()) # 判断所有字符都是数字
print(str.islower()) # 判断所有字符都是小写
print(str.isupper()) # 判断所有字符都是大写
print(str.istitle()) # 判断所有单词都是首字母大写，像标题
print(str.isspace()) # 判断所有字符都是空白字符、\t、\n、\r

print("------------------------")

# 测试实例二
print("测试实例二")
str = "Bake corN"
print(str.isalnum()) 
print(str.isalpha()) 
print(str.isdigit()) 
print(str.islower()) 
print(str.isupper()) 
print(str.istitle()) 
print(str.isspace())

str = "https://www.cnblogs.com/ailiailan/"
print(str.upper())          # 把所有字符中的小写字母转换成大写字母
print(str.lower())          # 把所有字符中的大写字母转换成小写字母
print(str.capitalize())     # 把第一个字母转化为大写字母，其余小写
print(str.title())          # 把每个单词的第一个字母转化为大写，其余小写

import calendar
monthRange = calendar.monthrange(2016,9)
print(monthRange)

# 引入 datetime 模块
import datetime
def getYesterday(): 
    today=datetime.date.today() 
    oneday=datetime.timedelta(days=1) 
    yesterday=today-oneday  
    return yesterday

# 输出
print(getYesterday())