forward ：Python - pandas DataFrame Data merging and splicing （merge、join、concat）
It's a comprehensive summary ！
For example, merge all the files in one folder ：
#merge
# import os
#import pandas as pd
# file_list = []
# path = r'input file path /'
# for file in os.listdir(path):
# df = pd.read_csv(path+file)
# file_list.append(df)
# all_VA = pd.concat(file_list)
# all_VA.to_csv(path+'5455.csv',index = False)
# print('done!')
About using Python to draw (set the line type to dotted line), my textbook is as shown in Figure 1 (in the black box), and the actual operation is as shown in Figure 2 (rose red)
So is the textbook wrong ？ Or
