Lesson 2 KeyPoints

int, float

1. int 為整數

2. float為 浮點數，帶有小數點的數， EX: 3.14

3. 浮點數因為硬體限制，無法無限精確，EX: print(0.1 + 0.2) # gives 0.30000000000000004

4. 支援科學記號，EX: print(3.9e9) ，輸出 3900000000.0

round()

1. 四捨五入

import

1. 引入額外的模組，EX: import math

2. 引入額外的模組中的特定部分， EX: from math import ceil

math 數學模組 部分函數與內容

• floor(x) — returns the largest integer less than or equal to x,

• ceil(x) — returns the smallest integer greater than or equal to x,

• sqrt(x) — returns the square root of x,

• log(x) — returns the natural logarithm of x,

• log(x,a) — returns the logarithm of x to base a,

• pi is the mathematical constant pi = 3,1415926..

• e — is the mathematical constant e = 2,71828..

• sin(x) returns the sine of x in radians

• cos(x) returns the cosine of x in radians

• tan(x) returns the tangent function of x

• asin(x) returns the arcsine of x in radians