Use python's matplotlib library to draw bar graphs, line graphs, and pie charts

The Excel in the office component we usually use has a relatively powerful drawing function, and can carry out a variety of images, such as bar graphs, line graphs, pie graphs, and even scatter graphs. It can even be used for text documents. Some simple images. But the images they draw are relatively fixed and relatively small in function.

Today we will introduce matplotlib, an important plotting library in python.
The matplotlib library is a third-party library of python. If you install IDLE of python, you need to install it additionally. Generally, what we install is that Anaconda (python integrated development environment) is already built-in and no additional installation is required.

1. Histogram

import matplotlib.pyplot as plt
plt.rcParams['font.sans-serif']=['SimHei'] #显示中文
x=[i for i in range(1,6)]
y=[2,4,3,6,7]
plt.bar(x,y,color='r',width=0.3)
plt.show()

The effect is shown in the figure.

This is the simplest histogram, and you can even remove the third row.

import matplotlib.pyplot as plt
plt.rcParams['font.sans-serif']=['SimHei'] #显示中文
y=[2,4,3,6,7]
plt.bar(x,y,color='r',width=0.3)
plt.show()

The effect is the same, the abscissa will be created by default at this time

• Tagging

plt.xlabel('得分')
plt.ylabel('人数')

• Caption

plt.title('成绩分析图')

• Custom abscissa label

heng=['小明','小红','小刚','小芳','小雨']
plt.bar(x,y,color='r',tick_label=heng,width=0.3)

• Rotate histogram direction

plt.barh(x,y,color='r',tick_label=hen,height=0.3)

• Save the picture to the same local directory

plt.savefig('picture.png')

To increase the clarity of the picture, you can set the dpi size

plt.savefig('picture.png',dpi=300)

• Complete code

import matplotlib.pyplot as plt
plt.rcParams['font.sans-serif']=['SimHei'] 

x=[i for i in range(1,6)]
y=[2,4,3,6,7]
heng=['小明','小红','小刚','小芳','小雨']
plt.bar(x,y,color='r',tick_label=heng,width=0.3)
plt.xlabel('同学')
plt.ylabel('分数')
plt.title('成绩分析图')
plt.savefig('picture.png')
plt.show()

The core code is only one sentence

plt.bar(x,y,color='r',tick_label=heng,width=0.3)

2. line chart

import matplotlib.pyplot as plt
plt.rcParams['font.sans-serif']=['SimHei'] 
y1=[1127968,1193973  ,1330385  ,1211292 , 1365868]

y2=[950600 , 967387  ,1102495 , 992571  ,1132938]

y3=[ 797236 , 872468  ,922418,  896010  ,950669]

y4=[405868  ,540142 , 682967  ,774129  ,789672]
x=[1,2,3,4,5]
plt.plot(x,y1,'r*--',linewidth=2.5,label='会员A')
plt.plot(x,y2,'b*--',linewidth=2.5,label='会员B')
plt.plot(x,y3,'g*--',linewidth=2.5,label='会员C')
plt.plot(x,y4,'y*--',linewidth=2.5,label='会员D')
plt.xlabel('天数')
plt.ylabel('伤害')
plt.legend()
plt.title('会员们的伤害变化')
plt.show()

The thickness of the control line becomes linewidth.

• Add legend

plt.plot(x,y1,'r*--',linewidth=2.5,label='会员A')
plt.legend()

Among them,'r*–','r' represents color,'*' represents, and'- -'represents the curve style is dashed line.

• colour

letter	Corresponding color
r	red
b	blue
g	green
and	yellow
k	black
w	white
m	purple
c	Blue

In fact, red, green, yellow, etc. can also be used to represent colors.

1. Discrete data point type

symbol	Means
.	Black spot
+	plus
*	Asterisk
The	Solid dot
d	diamond
p	Five-pointed star
h	Six-pointed star
x	X number
s	Cube

2. Continuous line

symbol	Means
-	solid line
- -	Dashed line
：	dotted line
-.	Dotted line

3. Pie chart

import matplotlib.pyplot as plt
plt.rcParams['font.sans-serif']=['SimHei'] 
d={
    
    '美国': 1368036, '英国':223060, '法国':176970, '巴西': 163510, '意大利':219070, 
   '俄罗斯':221344, '德国': 171999, '西班牙':268143, '土耳其':138657, '伊朗':109286,
   '其他':1069769}
a = sorted(d.items(), key=lambda x: x[1],reverse=True)
a=dict(a)   #处理数据
size=a.values()    #提取出数字
color=['red','blue','green','pink','orange','purple','yellow']   #分配颜色，若颜色不够，会循环已有的颜色
label=a.keys()   #提取出国家
explode=(0.05,0,0,0,0,0,0,0,0,0,0)
pie=plt.pie(size,explode=explode,colors=color,labels=label,
        autopct='%1.1f%%',startangle=90,counterclock=False)
        #核心代码
plt.show()