使用 Pyhton、Pandas 读取各种文件并将其写入一张 Excel 表格

Question

不管我做什么，我都没有把 xhtml 文件中的所有数据都写在一张 Excel 工作表中。 看起来，Python 遍历文件夹中的所有文件，但作为输出，我只从最后一个文件中获取数据。 帮助会很棒！

#!/usr/bin/python3

# Import libaries
import pandas as pd
import openpyxl
from openpyxl import load_workbook
import glob
import time

#Path to folder
path_dir: str = r"C:\Users\Moench\Desktop\r2d2\EPUB\content1\*.xhtml"

#Read files
for filename in glob.glob(path_dir):

#Assign the table data to a Pandas dataframe 
        dfs = open(filename, 'r')
        dfs1 = pd.read_html(dfs)

#Read data                                                                                                         
        df2 = dfs1[0][['Unnamed: 0_level_0','Unnamed: 1_level_0','Unnamed: 2_level_0','Unnamed: 3_level_0','Unnamed: 4_level_0','Unnamed: 12_level_0','Unnamed: 13_level_0']]
 
#Print result (Looks like that it goes through all files in the folder)
#        print (df2)

# Write to existing Excel-Sheet
book = load_workbook('output.xlsx')
writer = pd.ExcelWriter('output.xlsx', engine='openpyxl') 
writer.book = book
ts = time.time()

df3 = df2.append(df2) 
writer.sheets = dict((ws.title, ws) for ws in book.worksheets)
df3.to_excel(writer, str(ts))
writer.save()

Answer 1

您在每次迭代时将数据存储在同一个数据帧中，在每次迭代时重写它，因此您只有最后一个数据（实际上是两次，因为df2.append(df2) 。

这是一个稍微修改的版本，将每个数据帧存储在df_list ，并在此列表上使用pd.concat创建df3 ：

#!/usr/bin/python3

# Import libaries
import pandas as pd
import openpyxl
from openpyxl import load_workbook
import glob
import time

#Path to folder
path_dir: str = r"C:\Users\Moench\Desktop\r2d2\EPUB\content1\*.xhtml"

# Initiate list of dataframes
df_list = list()

#Read files
for filename in glob.glob(path_dir):

#Assign the table data to a Pandas dataframe 
        dfs = open(filename, 'r')
        dfs1 = pd.read_html(dfs)

#Read data                                                                                                         
        df2 = dfs1[0][['Unnamed: 0_level_0','Unnamed: 1_level_0','Unnamed: 2_level_0','Unnamed: 3_level_0','Unnamed: 4_level_0','Unnamed: 12_level_0','Unnamed: 13_level_0']]
       
        df_list.append(df2)
 
#Print result (Looks like that it goes through all files in the folder)
#        print (df2)

# Write to existing Excel-Sheet
book = load_workbook('output.xlsx')
writer = pd.ExcelWriter('output.xlsx', engine='openpyxl') 
writer.book = book
ts = time.time()

# Concatenate all dataframes into one
df3 = pd.concat(df_list, ignore_index=True) 

writer.sheets = dict((ws.title, ws) for ws in book.worksheets)
df3.to_excel(writer, str(ts))
writer.save()