Python基础（6）文件和I/O流

系统管理员 2022-05-23 04:21 36阅读 0赞

#coding=gbk
    #文本文件
    with open(r'C:\Users\Administrator\Desktop\mysal\Python\data.txt','r') as f:#with语句自动关闭文件流
        for s in f.readlines():#readlines()读入多行内容
            print(s,end="")
    with open(r'C:\Users\Administrator\Desktop\mysal\Python\data.txt','a') as f:#a为增加内容，w为先删除原内容，再增加内容
        f.write('\nhaha_number2')
    #二进制文件
    with open(r'C:\Users\Administrator\Desktop\mysal\Python\data1.dat','ab') as f:
        f.write(b'\nthis,world')#写入字节接数据
    print('-----------华丽的分割线---------')
    with open(r'C:\Users\Administrator\Desktop\mysal\Python\data1.dat','rb') as f:
        a=f.read();
        print(a)           
    #读取csv格式的文件    
    import csv
    filename='C:/Users/Administrator/Desktop/mysal/Python/data.csv'  #由于\存在转义符号的歧义，建议使用“/”符号
    with open(filename) as f:     
        reader = csv.reader(f)
        print(list(reader))
        
    import csv
    filename='C:/Users/Administrator/Desktop/mysal/Python/data.csv' 
    with open(filename) as f:
        reader=csv.reader(f)
        header_row=next(reader)#不读取第一行的属性
        for row in reader:
            print(reader.line_num,row)#从第二行开始读取
    # 输出为 2 ['bob', '15', 'male']
    # 3 ['smith', '27', 'female']
    # 4 ['junge', '23', 'male']
    # 5 ['liudehua', '45', 'male']    
    
    #在CSV中写入数据
    datas=[['zhangsan','34','female'],['wnagwu','36','male']]
    import csv
    filename='C:/Users/Administrator/Desktop/mysal/Python/data.csv'
    with open(filename,'a',newline='') as f: #a表示在元文件中增加datas
        reader=csv.writer(f)
        for row in datas:
            reader.writerow(row) #以当行写入
                                    #还可以以多行写入 reader.writerows(datas)
    
    #对象序列化，程序运行时对象创建在内存中，如果需要持久地保存在磁盘中，
    #或需要通过网络传递给其他机器，则需要通过对象序列化机制
    #对象序列化
    import pickle #应用模块
    with open(r'C:/Users/Administrator/Desktop/mysal/Python/demo.dat','ab') as f:
        s1='hello world'
        c1=1+1j
        d1=dict(name='hale',age=14)
        pickle.dump(s1,f)
        pickle.dump(c1,f)
        pickle.dump(d1,f)