标签:def 元素 练习 练习题 元组 utf-8 result shuff shuf
andom模块>> random.random()
0.15331915985695865
>> random.random()
0.6973041759495626>> round(random.random()*100)
13
>> str(random.random())[2:]
‘5091957416488744‘
随机生成100以内的两位数
>> int(random.random()*100)
11
random.randint(a,b)
随机生成a,b之间的一个整数,左右都是闭区间
>> random.randint(1,100)#都是闭区间
10
random.randrange(a,b)
随机生成a,b之间的一个整数,左开区间,右闭区间
>> random.randrange(1,100)#右边开区间
2
random.choice(seq)
随机返回序列中的一个元素值,有返回值
>> random.choice("abc")#字符串
‘a‘
>> random.choice(["a","b","c"])#列表
‘c‘
>> random.choice(("a","b","c"))#元组
‘b‘>> c = random.choice("abc")
>> c
‘b‘
random.shuffle(list)
打乱列表list的元素顺序,只能针对列表,没有返回值
>> l = list(range(10))
>> random.shuffle(l)
>> l
[0, 3, 6, 9, 1, 8, 2, 5, 4, 7]
>> random.shuffle(l)
>> l
[8, 3, 7, 6, 4, 9, 0, 2, 5, 1]
random.uniform()
uniform()?方法将随机生成下一个实数,它在?[x, y)?范围内。返回一个浮点数,有返回值>> random.uniform(1,100)
28.62268392118385
>> f = random.uniform(1,3)
>> f
2.7439797786402718
random.sample(population,n)
在population中随机选取n个元素,返回一个列表;
population 可以是序列和集合,包含列表、元组、字符串和集合
>> import string
>> random.sample(string.ascii_letters,3)#字符串
[‘f‘, ‘a‘, ‘X‘]>> l = list(range(1000))
>> random.sample(l,5)#列表
[776, 22, 715, 798, 982]>> t = (1,2,3,4,5,6,7,8,9,10)
>> random.sample(t,4)#元组
[3, 9, 2, 4]
>> set1 = set(list(range(1000)))
>> random.sample(set1,10)#集合
[520, 405, 874, 301, 879, 597, 764, 428, 107, 268]>> result_list = random.sample(set1,10)
>> print(result_list)
[853, 218, 487, 955, 549, 990, 166, 557, 650, 615]
练习题:
1、生成9位数字的密码
一、
#coding =utf-8
import random
numbers_passwd = ""
for i in range(9):
numbers_passwd += str(random.randint(0,9))
print(numbers_passwd)
二、
#coding =utf-8
import random
numbers_passwd = ""
for i in range(9):
numbers_passwd += "0123456789"[random.randint(0,9)]
print(numbers_passwd)
2、生成9位字母的密码
#coding =utf-8
import random
import string
letters_passwd = ""
for i in range(9):
letters_passwd += string.ascii_letters[random.randint(0,52)]
print(letters_passwd)
3、生成9位数字和字母的密码
#coding =utf-8
import random
import string
number_letter_passwd = ""
for i in range(9):
if random.randint(0,1):#如果是随机生成的1生成一个字母密码元素
number_letter_passwd += string.ascii_letters[random.randint(0,52)]
else:#否则生成数字密码元素
number_letter_passwd += str(random.randint(0,9))
print(number_letter_passwd)
sys.exit(1)退出程序
#coding=utf-8
import sys
print(1)
sys.exit(1)
print(2)
浮点数之坑
>> 10-9.9
0.09999999999999964
>> 10100 - 9.9100
10.0
>> (10100 - 9.9100)/100
0.1
练习题:
1、10进制数转换成2进制
#coding =utf-8
def devTobin(num):
result = []
while True:
result.append(str(num%2))
num = num//2
if num ==0:
break
return "".join(result[::-1])
print(devTobin(789))
3、二进制转换为十进制
101 = 1*2^0 + 0*2^1 + 1*2^2 = 5
#coding =utf-8
def binTodev(binNum):
result = 0
number_length = len(binNum)
for i in range(number_length):
#print("i:",i)
#print(binNum[i])
result += int(binNum[-(i+1)])*pow(2,i)#二进制的数要从右边开始取,从-1开始
return result
print(binTodev("1100010101"))
标签:def 元素 练习 练习题 元组 utf-8 result shuff shuf
原文地址:http://blog.51cto.com/13496943/2165981