from math import *
import sys
# print(sys.path)
#九九乘法表
for i in range(1,10):
    for j in range(1,i+1):
        print(i,'*',j,'=',i*j,'\t',end=' ')
    print()
(一)
digits = (1,2,3,4)
for i in digits:
    for j in digits:
        for k in digits:
            if i!=j and j!=k and i!=k:
                print(i*100 + j*10 +k,end = ' ')
else:
    print()
(二)
digits = 1,2,3,4
for i in digits:
    for j in digits:
        if i==j:
            continue
        for k in digits:
            if k==i or k==j:
                continue
            print(i*100 + j*10 + k,end=' ')
print()
#随机生成20个1到100的互不相同的数字(1)
import random
x = []
while True:
    if len(x)==20:
        break
    n=random.randint(1,100)
    if n not in x:
        x.append(n)
print(x)
print(len(x))
print(sorted(x))
print(sorted(x,reverse=True))
#随机生成20个1到100的互不相同的数字(2)
#一行搞定
x=[random.randint(1,100) for i in range(20)] print(x) print(len(x)) print(sorted(x)) print(sorted(x,reverse=True))
 
 
print('the number {0:,} in hex is : {0:#x},the number {1} in oct is {1:#o}'.format(5555,55))
print('my name is {name},my age is {age},my qq is {qq}'.format(name='Teng',age=1,qq=1825587919))
print('my name is %s,my age is %d,my qq is %s' % ('teng',1,'1825587919'))
position = (5,6,7)
print('x:{0[0]}'.format(position))
#find()
#rfind()
#index()  //如果不在抛出异常
#rindex() //same
#count()
#split()
#rsplit()
#partition()
#rpartition()
#jion() //组合
s = 'apple,peach,banana,pera'
li = s.split(',')
print(li)
ll='  '.join(li)
print(ll)
print(ll.split())
print(s.partition(','))
print(s.rpartition(','))
print(s.partition('banana'))
s= '2018-3-13'
print(s.split('-'))
map(int,s.split('-'))
#lower()  //转为小写
#upper()  //转为大写
#capitalize()//首字母大写
#title()//每个单词首字母大写
#swapcase()//大小写转换
s = 'What is Your Name ? '
y = "I'am Teng"
st = s+y
print(st.lower())
print(st.upper())
print(st.capitalize())
print(st.title())
print(st.swapcase())
#replace()//替换
#maketrans()
#translate()
print(st.replace('a','O'))
#strip() //删除两端空白或指定字符
#rstrip()
#lstrip
s = '    sdf   '
print(s.strip())
print('\n\n hello dfdf \n\t'.strip())
print('sssfgfgssrg'.strip('sf'))    #只要连续包含字符串中某个字符就ok
print('ssssssdfgdfddss'.lstrip('s'))
print('ssssssdfdfssss'.rstrip('s'))
#eval()尝试把任意字符串转化为python表达式并求值
print(eval('33-4'))
#危险操作
a= "__import__('os').startfile(r'C:\Windows\\notepad.exe')"
eval(a)
#startswith()
#endswith()
#isalpha
#isalnum
#...
#center()
#ljust()
#rjust()
print('hello'.center(1))
print('hello'.center(20))
print('hello'.center(20,'_'))
print('hello'.ljust(20,'_'))