相信有不少的小伙伴在学函数图像，我直接把代码奉上

from matplotlib import pyplot as plt
import matplotlib as mpl
from math import *


def draw_graph(functions, sampling_density = 2.0, show_legend = True, dot_size = 20, scatter_or_line_chart = "scatter", scatter_style = "b,o", line_chart_style = "b,o,--,t", x_label = "x->", y_label = "y->", phase_line = True, multicolor = ["nullptr"], multiple_overlapping_images = [1], legend_of_each = ["nullptr"]):
    """
    :param functions: type = <list [function1, function2, ...]> For each function, given x, return y.
    :param sampling_density: type = <int (>= 1)> The frequency of sampling, the higher the clarity.
    :param show_legend: type = <bool True or False> Is the legend displayed.
    :param dot_size: type = <int (>= 1)> The size of each point.
    :param scatter_or_line_chart: <string "scatter" or "line_chart"> Draw a scatter or line chart.
    :param scatter_style: <string a,b> When drawing a scatter plot, color a and shape b.
    :param line_chart_style: <string a,b,c,d> When drawing a line chart, the color a, the shape of the point b, and the shape of the line c. When d=t, scatter points are displayed; otherwise, scatter points are not displayed.
    :param x_label: type = <string> Identification of the x-axis.
    :param y_label: type = <string> Identification of the y-axis.
    :param phase_line: type = <bool True or False> Is the phase line displayed.
    :param multicolor: type = <list [color1, color2, ...]> The color of each line or image, if used by default, please set it to ["nullptr"].
    :param multiple_overlapping_images: type = <list [l1, l2, ...]> Stack li images within i charts on the ground.
    :param legend_of_each: type = <list [legend1, legend2, ...]> The icon name for each icon, if not needed, please set it to ["nullptr"].
    :return: Based on the above parameters, draw and display the image.
    """
    mpl.rcParams['font.sans-serif'] = ['SimHei']
    mpl.rcParams['axes.unicode_minus'] = False
    data_of_subplot = {
        1: [1, 1], 2: [1, 2],
        3: [1, 3], 4: [2, 2],
        5: [2, 3], 6: [2, 3],
        7: [2, 4], 8: [2, 4],
        9: [3, 3], 10: [2, 5]
    }

    start = -(100 / 10 ** (sampling_density - 1))
    end = 100 / 10 ** (sampling_density - 1)
    add = end / 100
    function_pos = -1
    sub_cnt_pos = 1
    sub_cnt = len(multiple_overlapping_images)
    plt.figure(figsize = (4 * data_of_subplot[sub_cnt][1], 4 * data_of_subplot[sub_cnt][0]))
    for i in multiple_overlapping_images:
        plt.subplot(data_of_subplot[sub_cnt][0], data_of_subplot[sub_cnt][1], sub_cnt_pos)
        legends = []
        for j in range(i):
            x_coordinate = []
            y_coordinate = []
            function_pos += 1
            x = start
            if legend_of_each[0] == "nullptr":
                legends.append('f' + str(function_pos + 1))
            else:
                legends.append('$' + legend_of_each[function_pos] + '$')
            while (x <= end):
                try:
                    y = functions[function_pos](x)
                except ValueError:
                    x = 0 + add
                    continue
                if y >= start and y <= end:
                    x_coordinate.append(x)
                    y_coordinate.append(y)
                x += add
            plt.xlim(start, end)
            plt.ylim(start, end)
            plt.xlabel(x_label)
            plt.ylabel(y_label)
            if scatter_or_line_chart == "scatter":
                style = scatter_style.split(',')
                if multicolor[0] == "nullptr":
                    plt.scatter(x_coordinate, y_coordinate, s = dot_size, c = style[0], marker = style[1])
                else:
                    plt.scatter(x_coordinate, y_coordinate, s = dot_size, c = multicolor[function_pos], marker = style[1])
            elif scatter_or_line_chart == "line_chart":
                style = line_chart_style.split(",")
                if multicolor[0] == "nullptr":
                    plt.plot(x_coordinate, y_coordinate, color = style[0], linestyle = style[2])
                else:
                    plt.plot(x_coordinate, y_coordinate, color = multicolor[function_pos], linestyle = style[2])
                if style[3] == 't':
                    if multicolor[0] == "nullptr":
                        plt.scatter(x_coordinate, y_coordinate, s = dot_size, c = style[0], marker = style[1])
                    else:
                        plt.scatter(x_coordinate, y_coordinate, s = dot_size, c = multicolor[function_pos], marker = style[1])
        if phase_line:
            plt.plot([0, 0], [-100, 100], color = 'gray', linewidth = 1, alpha = 0.5)
            plt.plot([-100, 100], [0, 0], color = 'gray', linewidth = 1, alpha = 0.5)
        if show_legend and scatter_or_line_chart == "line_chart":
            plt.legend(legends, loc = 'upper right')
        sub_cnt_pos += 1
    plt.show()

def f1(x):
    return x ** 2

def f2(x):
    return sin(x)

def f3(x):
    return cos(x)

def f4(x):
    return tan(x)

def f5(x):
    return x ** 2 / 2

def f6(x):
    return -(x ** 2 / 2)

def f7(x):
    return -(x ** 2 / 3)

def f8(x):
    return (x ** 2 / 2)

def f9(x):
    return log(x, 2)

def f10(x):
    return x ** 3 - x ** 2

def f11(x):
    return x ** 4 - x ** 3

def f12(x):
    return x ** 2 * 2

def f13(x):
    return -x

def f14(x):
    return x

def f15(x):
    return x * 5

draw_graph([f1, f2, f3, f4, f5, f6, f7, f8, f9, f10, f11, f12, f13, f14, f15],
        scatter_or_line_chart = "line_chart", multicolor = ['black', 'red', 'green', 'blue', 'pink', 'yellow', 'orange', 'blue', 'green', 'black', 'red', 'yellow', 'green', 'gray', 'blue'],
        multiple_overlapping_images = [1, 3, 2, 2, 1, 2, 1, 2, 1],
        legend_of_each = ['x^2', 'sin(x)', 'cos(x)', 'tan(x)', 'x^2/2', '-x^2/2', '-x^2/3', 'x^2/3', 'log(2,x)', 'x^3-x^2', 'x^4-x^3', '2x^2', '-x', 'x', '5x']
)