Python文件操作

f = open("test.txt","r",encoding=‘utf-8‘)
data = f.read()
print(data)
f = open("test.txt","w",encoding=‘utf-8‘)#写入，是通过创建新文件的方式，如果有重复的名字的文件，会清空旧的内容。
f.write("呵呵哒\n")#\n是换行符
f.close()#关闭文件

f = open("test.txt","a",encoding=‘utf-8‘)
f.write("呵呵哒")
f.close()

# Cheng
f = open("test.txt","r",encoding=‘utf-8‘)
print(f.readline())#读一行
f.close()

f = open("test.txt","r",encoding=‘utf-8‘)
for i in range(5):　　#读五行
    print(f.readline())
f.close()

# Cheng垃圾的写法
f = open("test.txt","r",encoding=‘utf-8‘)
count = 0
for line in f.readlines():
    if count <= 9:#取出前十行
        print(line.strip())
        count += 1
    else:
        exit()
f.close()

# Cheng
f = open("test.txt","r",encoding=‘utf-8‘)
count = 0
for line in f:#因为文件指针不会往回走，所以也是逐行。
    if count <= 9:
        print(line)
        count += 1
    else:
        exit()
f.close()