python文件操作02 文件指针
# 一:读相关操作 # 1、readline:一次读一行 # with open(r'g.txt',mode='rt',encoding='utf-8') as f: # # res1=f.readline() # # res2=f.readline() # # print(res2) # 2、readlines: # 将文件内容按换行符分别存到一个List里面,列表内元素含换行符 with open(r'g.txt',mode='rt',encoding='utf-8') as f: res=f.readlines() print(res) # readline和readlines这种一次读入所有文件内容的操作很危险
# 二:写相关操作 # f.writelines(): with open('h.txt',mode='wt',encoding='utf-8') as f: # # f.write('1111\n222\n3333\n') # # # l=['11111\n','2222','3333',4444] l=['11111\n','2222','3333'] # # for line in l: # # f.write(line) f.writelines(l) #替代上面的循环的作用 # writelines() 将列表按列表元素分别写入指定文件 # t模式下,所有被写入的文件内容须均为str类型,否则会报错