将完整数据写入fi

Question

我有一个python脚本，它解析sqlitedb表中的数据并将其写入文本文件

它在工作，但它不断地写最后一行一遍又一遍。我曾尝试使用“a+”参数附加到文件中，但它似乎错过了之前的一切，只写最后一行。有没有理由不将控制台中所有解析的数据保存到文件中

# Script that parses data from the sms table contained in the mmssms database (text message database)

# import statements
import sqlite3, datetime
from sqlite3 import Error
import csv


# create a database connection to the SQLite database specified by the db_file
def create_connection(db_file):
    try:
        conn = sqlite3.connect(db_file)
        return conn
    except Error as e:
        print(e)

    return None

# Query specific rows in the sms table
def select_data(conn):
    cur = conn.cursor()
    cur.execute("SELECT _id, date, date_sent, read, type, body, seen FROM sms")
    print("Outputting the contents of the sms table within the mmssms.db database file")
    print("\t")

    # Write the data to a txt file
    with open('smsEvidence.txt', 'a+') as f:
        rows = cur.fetchall()
        for row in rows:
            print(row)
        f.write("%s\n" % str(row))
        print("Data is Written To txt File")




# path to where the db files are stored
def main():
    database = "H:\College Fourth Year\Development Project\Final Year Project 2018\mmssms.db"

     # create a database connection
    conn = create_connection(database)
    with conn:

        # print("Query specific columns")
        select_data(conn)
    # close db connection
    if(conn):
        conn.close()
        print("Database closed")


if __name__ == '__main__':
    main()