W2.md

1.通讯录

number={
    'hushiruo':'1234567',
    'huangyujie':'87654321',
    'xueqing':'66666666'
}

2.平方

a_list = [1,2,3,4,5]
squared_list = [0 for i in range(5)]
for i in range(5):
    squared_list[i] = a_list[i]**2

print(squared_list)

[1, 4, 9, 16, 25]

3.类

class cat:
    #属性
    color = ''
    jump = 0
    #构造
    def __init__(self, c, j):
        self.color = c
        self.jump = j

cc = cat('red',2)
print(cc.color)
print(cc.jump)

red
2

4.函数式

item = [1,2,3]
squared = list(map(lambda x: x**2, item))
print(squared)

[1, 4, 9]

5.一元二次方程

import math
def solve_equ(b,c):
    val1 = b/2.0
    val2 = val1**2
    val3 = val2+c
    val4 = math.sqrt(val3)
    root1 = val4-val1
    root2 = -val4-val1
    return root1,root2

print(solve_equ(10,39))

(3.0, -13.0)

6.PI

import random
import math

def draw(inner_points,outer_points):
    import matplotlib.pyplot as plt
    fig, ax = plt.subplots(figsize=(5, 5))
    inner_x = [x[0] for x in inner_points]
    inner_y = [x[1] for x in inner_points]
    outer_x = [x[0] for x in outer_points]
    outer_y = [x[1] for x in outer_points]
    ax.scatter(inner_x, inner_y, color="r",s=1)
    ax.scatter(outer_x, outer_y, color="g",s=1)

    ax.set_xlim(0, 1)
    ax.set_ylim(0, 1)

    import numpy as np
    theta = np.linspace(0, 2*np.pi, 100)
    r = 1
    x1 = r*np.cos(theta)
    x2 = r*np.sin(theta)
    ax.plot(x1, x2,color='black')
    plt.show()

def MonPi(number):
    N2 = number
    N1 = 0.
    inner_points = []
    outer_points = []
    for i in range(N2):
        x = random.random()
        y = random.random()
        if x*x+y*y<=1:
            N1+=1
            inner_points.append([x,y])
        else:
            outer_points.append([x,y])
    
    print("Monte PI:",4*N1/N2)
    draw(inner_points,outer_points)

def TaylorPi(k):
    sum,odd = 0,True
    for i in range(1,k):
        sum += 1/(2*i-1) if odd==True else -1/(2*i-1)
        odd = not odd
    print("Taylor PI:",sum*4)

MonPi(30000)
TaylorPi(100000)

Monte PI: 3.138933333333333

Taylor PI: 3.1416026536897204

7.画图

import matplotlib 
import matplotlib.pyplot as plt
import numpy as np

t = np.arange(0, 3*np.pi, 0.1)
s = np.sin(t)
c = np.cos(t)

plt.subplot(2,1,1)

plt.plot(t,s)
plt.title('Sine')

plt.subplot(2,1,2)
plt.plot(t,c)
plt.title('Cosine')

plt.show()

8.GUI

from tkinter import *