python数据可视化之matplotlib

用matplotlib进行数据可视化探索

一.柱状图

import matplotlib.pyplot as pltimport matplotlibimport pandas as pdimport numpy as np

def bar_plot():    """    bar plot    """    # 生成测试数据    means_men = (20, 35, 30, 35, 27)    means_women = (25, 32, 34, 20, 25)    # 设置标题    plt.title("title")    # 设置相关参数    index = np.arange(len(means_men)) #横坐标    bar_width = 0.35 #宽度    # 画柱状图    plt.bar(index, means_men, width=bar_width, alpha=0.2, color="b", label="boy")  #alpha是透明度    plt.bar(index+bar_width, means_women, width=bar_width, alpha=0.8, color="r", label="girl")  #加上bar_width是为了并列放置，否则会堆在一起    plt.legend(loc="upper center", shadow=True) #设置图例位置    # 设置柱状图标示，上面的数字    for x, y in zip(index, means_men):        plt.text(x, y+0.5, y, ha="center", va="bottom")  #ha是水平对齐，va是垂直对齐    for x, y in zip(index, means_women):        plt.text(x+bar_width, y+0.5, y, ha="center", va="bottom")    # 设置刻度范围/坐标轴名称等    plt.ylim(0, 50)    plt.xlabel("Group")    plt.ylabel("Scores")    plt.xticks(index+(bar_width/2), ("A", "B", "C", "D", "E"))    # 图形显示    plt.show()    return
bar_plot()