Python creates a csv file, appends data, and does not leave blank rows of data

 Create a csv file, and determine whether the csv file exists before appending data

example

import csv
import os

csv_header = ['time', 'temp', 'gas']
file_name = 'model_data.csv'

if not os.path.exists(file_name):  #文件不存在
    with open(file_name, 'w', encoding='utf8', newline='') as file:
        writer = csv.writer(file)
        writer.writerow(csv_header)
            
with open(file_name, 'a+', encoding='utf8', newline='') as file:
    writer = csv.writer(file)
    writer.writerow([1, 10, 20])
    writer.writerow([2, 11, 20])

Append data, pay attention to open with 'a+' mode in open() . 

Do not leave a blank line of data, specify the parameter newline=''