1. 最基本的讀文件方法:
File: readline-example-1.py
file = open("sample.txt")
while 1:
line = file.readline()
if not line:
break
pass # do something
一行一行得從文件讀數據,顯然比較慢;不過很省內存。
2. 用fileinput模塊
# File: readline-example-2.py
import fileinput
for line in fileinput.input("sample.txt"):
pass
3. 帶緩存的文件讀取
# File: readline-example-3.py
file = open("sample.txt")
while 1:
lines = file.readlines(100000)
if not lines:
break
for line in lines:
pass # do something
在Python 2.2以後,我們可以直接對一個file對象使用for循環讀每行數據:
# File: readline-example-5.py
file = open("sample.txt")
for line in file:
pass # do something
而在Python 2.1裏,你只能用xreadlines迭代器來實現:
# File: readline-example-4.py
file = open("sample.txt")
for line in file.xreadlines():
pass # do something