數(shù)字類型及操作
整數(shù)類型
a = pow(2, 3)
print(a)
二進制：0b或0B開頭
八進制：0o或0O開頭
十六進制：0x或0X開頭
浮點數(shù)類型
round(x, d) #四舍五入函數(shù)，d截取小數(shù)位數(shù)
浮點數(shù)的科學(xué)計數(shù)法表示
<a>e<b> ----> a*10^b
復(fù)數(shù)類型
z = 7.77e + 77j
a = z.real #實部
b = z.imag #虛部
數(shù)值類型及操作
| 操作符及使用 |
描述 |
| x + y |
x, y之和 |
| x - y |
x, y之差 |
| x * y |
x, y之積 |
| x / y |
x, y之商 10/3=3.3333 |
| x // y |
x, y之整數(shù)商 10//3=3 |
| x % y |
模運算，返回除法余數(shù) 5%2=1 |
| x ** y |
冪運算，x^y |
| x += y |
x = x + y |
| x -=y |
x = x - y |
| x *=y |
x = x * y |
| x /=y |
x = x / y |
| x %=y |
x = x % y |
| x **=y |
x = x ** y |
| x //=y |
x = x // y |
數(shù)值運算函數(shù)
| 函數(shù)及使用 |
描述 |
| int(x) |
直接舍棄小數(shù)部分，將x變?yōu)檎麛?shù) |
| float(x) |
增加小數(shù)部分，將x變?yōu)楦↑c數(shù) |
| complex(x) |
增加虛部部分，將x變?yōu)閺?fù)數(shù) |
實例
# example 1 天天向上
# 讀取鍵入變量
a = input("print your variable：")
# 每天進步一點點
dayup = pow(1+a, 365)
# 每天退步一點點
daydown = pow(1-a, 365)
# 輸出打印
print("dayup : {:.2f}, daydown : {:.2f}".format(dayup, daydown))
def dayUp(a):
dayup = 1
for i in range(365):
if i % 7 in [0,6]:
dayup = dayup * (1 - 0.01)
else:
dayup = dayup * (1 + a)
return dayup
a = 0.01
while dayUp(a) < 37.78:
a += 0.001
print("工作日努力參數(shù)：{:.3f}".format(a))
字符串類型及操作
字符串操作符
| 操作符及使用 |
描述 |
| x + y |
連接字符串x, y |
| n * x 或 x * n |
復(fù)制n次字符串x |
| x in s |
如果x是s的子串，返回True；否則False |
eval() #去掉最外層引號
| 字符串處理函數(shù) |
描述 |
| len(x) |
返回字符串x的長度 |
| str() |
返回任意類型x的字符串形式 |
| hex(x) |
返回整數(shù)x的十六進制的字符串類型 |
| oct(x) |
返回整數(shù)x的八進制的字符串類型 |
| 字符串處理方法 |
描述 |
| str.lower() |
返回小寫字符 |
| str.upper() |
返回大寫字符 |
| str.split() |
對字符串切片 |
| str.count(sub) |
返回字串sub在str中出現(xiàn)的次數(shù) |
| str.replace(a, b) |
將a替換為b |
| str.center(width, fillchar) |
在width內(nèi)str居中 |
| str.strip(chars) |
從str中刪去其左右兩側(cè)chars中所列出的字符 |
| str.join(iter) |
用str分割字符串iter |
time庫的使用
| 函數(shù) |
描述 |
| time() |
time.time()獲取當前時間戳 |
| ctime() |
time.ctime()獲取當前時間并以易讀方式表示 |
| gmtime() |
time.gmtime()獲取當前時間，可調(diào)取的時間格式 |
import time
Time = time.time()
CTime = time.ctime()
GMtime = time.gmtime()
print('time.time():', Time)
print('time.ctime():', CTime)
print('time.gmtime()', GMtime)
time.time(): 1579741343.4657865
time.ctime(): Thu Jan 23 09:02:23 2020
time.gmtime() time.struct_time(tm_year=2020, tm_mon=1, tm_mday=23, tm_hour=1, tm_min=2, tm_sec=23, tm_wday=3, tm_yday=23, tm_isdst=0)
import time
start = time.perf_counter()
wait = time.sleep(7)
end = time.perf_counter()
timekeeping = end - start
print('Timekeeping:', timekeeping)
Timekeeping: 7.000483000000031
import time
scale = 50
print('Start'.center(scale, '-'))
start = time.perf_counter()
for i in range(scale+1):
a = '*' * i
b = '.' * (scale-i)
c = (i/scale) * 100
timekeeping = time.perf_counter() - start
print('{:^3.0f}%[{}->{}]{:.2f}s'.format(c,a,b,timekeeping))
time.sleep(0.1)
print('\n' + 'End'.center(scale, '-'))
----------------------Start-----------------------
0 %[->..................................................]0.00s
2 %[*->.................................................]0.10s
4 %[**->................................................]0.20s
6 %[***->...............................................]0.30s
8 %[****->..............................................]0.40s
10 %[*****->.............................................]0.50s
12 %[******->............................................]0.60s
14 %[*******->...........................................]0.70s
16 %[********->..........................................]0.80s
18 %[*********->.........................................]0.90s
20 %[**********->........................................]1.01s
22 %[***********->.......................................]1.11s
24 %[************->......................................]1.21s
26 %[*************->.....................................]1.31s
28 %[**************->....................................]1.41s
30 %[***************->...................................]1.51s
32 %[****************->..................................]1.61s
34 %[*****************->.................................]1.71s
36 %[******************->................................]1.81s
38 %[*******************->...............................]1.91s
40 %[********************->..............................]2.01s
42 %[*********************->.............................]2.11s
44 %[**********************->............................]2.21s
46 %[***********************->...........................]2.31s
48 %[************************->..........................]2.41s
50 %[*************************->.........................]2.51s
52 %[**************************->........................]2.62s
54 %[***************************->.......................]2.72s
56 %[****************************->......................]2.82s
58 %[*****************************->.....................]2.92s
60 %[******************************->....................]3.02s
62 %[*******************************->...................]3.12s
64 %[********************************->..................]3.22s
66 %[*********************************->.................]3.32s
68 %[**********************************->................]3.42s
70 %[***********************************->...............]3.52s
72 %[************************************->..............]3.62s
74 %[*************************************->.............]3.72s
76 %[**************************************->............]3.82s
78 %[***************************************->...........]3.92s
80 %[****************************************->..........]4.02s
82 %[*****************************************->.........]4.13s
84 %[******************************************->........]4.23s
86 %[*******************************************->.......]4.33s
88 %[********************************************->......]4.43s
90 %[*********************************************->.....]4.53s
92 %[**********************************************->....]4.63s
94 %[***********************************************->...]4.73s
96 %[************************************************->..]4.83s
98 %[*************************************************->.]4.93s
100%[**************************************************->]5.03s
-----------------------End------------------------
# 單行刷新
import time
scale = 50
print('Start'.center(scale, '-'))
start = time.perf_counter()
for i in range(scale+1):
a = '*' * i
b = '.' * (scale-i)
c = (i/scale) * 100
timekeeping = time.perf_counter() - start
print('\r{:^3.0f}%[{}->{}]{:.2f}s'.format(c,a,b,timekeeping), end='')
time.sleep(0.1)
print('\n' + 'End'.center(scale, '-'))
----------------------Start-----------------------
100%[**************************************************->]5.03s
-----------------------End------------------------
