f = open("yesterday","r",encoding="utf-8")
#print(f.read())
#for i in range(5):
#    print(f.readline()) #打印前5行

#low loop
‘‘‘
for index,line in enumerate(f.readline()):
    if index == 9:
        print(‘---------我是分割線---------‘)
        continue
    print(line.strip())
‘‘‘

# high bige
‘‘‘
count =0
for line in f:
    if count==9:
        print(‘---------我是分割線-----‘)
        count +=1
        continue
    print(line) #效率最高，一行一行的讀
    count +=1
‘‘‘
f =open("yesterday2","w",encoding="utf-8")
f.write("hello1\n")
f.write("hello2\n")
f.write("hello3\n")
f.flush()#實現數據從緩存刷到硬盤

‘‘‘
print(f.tell()) #查詢光標位置
print(f.readline())
print(f.tell())#查詢光標位置,按字符計數
print(f.read(5))
print(f.tell())
f.seek(0)#光標回到某個字符位置
print(f.readline())
f.seek(10)
print(f.readline())
print(f.encoding)#打印文件編碼
print(f.fileno()) #讀取文件編號
#print(f.flush())
print(dir(f.buffer))
‘‘‘

‘‘‘#進度條實現
import sys,time

for i in range(50):
    sys.stdout.write("#")
    sys.stdout.flush()
    time.sleep(0.1)
‘‘‘

f = open("yesterday","a+",encoding="utf-8")#追加讀寫
#f.truncate(10) #截斷
f.seek(10)
f.truncate(20)

#可以打開，追加
f = open("yesterday","r+",encoding="utf-8")#讀寫
print(f.readline())
print(f.readline())
print(f.readline())
print(f.tell())
f.write(‘--------niu----------‘)

#用處不大
f = open("yesterday","w+",encoding="utf-8")#寫讀
f.write(‘--------niu----------1\n‘)
f.write(‘--------niu----------2\n‘)
f.write(‘--------niu----------3\n‘)
print(f.tell())
f.seek(10) #不能在中間插入，只能繼續往後寫，或者覆蓋之前的
print(f.tell())

#使用場景：網絡傳輸只能用二進制
f = open("yesterday","rb")#以二進制格式讀文件
print(f.readline())
print(f.readline())
print(f.readline())

f = open("yesterday","wb")#以二進制格式寫文件
f.write("hello binary\n".encode())

f = open("yesterday","ab")#以二進制格式追加文件

Python學習之路：文件操作之增刪改查