读取指定单行:

#读取单行文本
def file_read(line_target):#传入的参数为要获取文本的目标行数
    with open('Test.txt', 'r',encoding='utf-8') as file:#打开指定文本文件
        for num, line in enumerate(file):#num从0开始循环,所以对应的行数要减一
            if num == line_target-1:#当行数循环到等于传入的参数值减一时,返回这一行的文本内容并跳出循环
                return line
                break

一次读取所有文本并按行赋值到列表:

SaveList=[]#存档列表

#读取文本内容到列表
with open("Test.txt","r",encoding='utf-8') as file:
    for line in file:
        line=line.strip('\n')#删除换行符
        SaveList.append(line)
    file.close()

把列表里的元素按行写入文本文件:

#写入存档到文件
with open("Test.txt","w",encoding='utf-8') as file:
	for i in SaveList:
		file.write(i+'\n')
	file.close()

以追加而不是覆盖的方式在文件末尾写入行:

with open("Test.txt","a",encoding='utf-8') as file:
	file.write("文本内容\n")
	file.close()