Python practical series | Regular data extraction and drawing

##In this issue, I will share with you "Python Practical Combat" The first article in the series ": Regular extraction of data and drawing, this series mainly comes from the actual problems of fans, and will be continuously updated in the future, I hope it will be helpful to you. If you have any questions or areas that need improvement, you can send a private message to the editor.

Task description: Take the language data of the txt file to draw a line chart, The screenshot of the data.txt file is as follows (it’s too long and I’ll cut it straight):

## At first glance, it looks like a json format file. In fact, it looks like a json format file. The above is not

Let’s get to the point:

## ?️‍? 1. Read the data

with open('data.txt') as f:
    data = f.read()

?️‍? 2. Regularly extract the information inside curly braces {}

datas = re.findall('({.*?})',data)

#The content is basically the proportion of each date in the programming language. The next step is to extract the date information and data information.

## ?️‍? 3. Extract name, pay attention to escaping (')

re.findall('\'(.*)\'',datas[0])[0]

?️‍? 4. Extract date and data, pay attention to the decimal point of the data

re.findall('(\d+(\.\d+)?)',datas[0])

Every 4 Each data is a group, so just make a loop of step=4:

for i in range(0,len(datas_tmp),4):
    datas_f.append(float(datas_tmp[i+3][0]))
    dates_f.append(f'{datas_tmp[i][0]}-{datas_tmp[i+1][0]}-{datas_tmp[i+2][0]}')

?️‍? 5. Data extraction part Complete code

# 处理数据
with open('data.txt') as f:
    data = f.read()
datas = re.findall('({.*?})',data)
names = []
dates_result = []
datas_result = []
for idx,dd in enumerate(datas):
    datas_f = []
    dates_f = []
    name = re.findall('\'(.*)\'',dd)[0]
    names.append(name)
    datas_tmp = re.findall('(\d+(\.\d+)?)',dd)
    for i in range(0,len(datas_tmp),4):
        datas_f.append(float(datas_tmp[i+3][0]))
        dates_f.append(f'{datas_tmp[i][0]}-{datas_tmp[i+1][0]}-{datas_tmp[i+2][0]}')
    datas_result.append(datas_f)
    dates_result.append(dates_f)

?️‍? 6. 绘图

绘图部分直接用matplotlib的plot循环绘制即可，代码如下：

# 绘图
plt.figure(figsize=(20, 10), dpi=100)
for i in range(len(names)):
    plt.plot(dates_result[i], datas_result[i], label=names[i])
ax = plt.gca()
ax.xaxis.set_major_locator(ticker.MultipleLocator(20))
plt.ylabel("Ratings(%)", fontdict={'size': 16})
plt.title("TIOBE Programming Community Index", fontdict={'size': 20})
plt.legend(loc='best')
plt.grid(True, linestyle='--', alpha=0.5)
plt.show()

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