truncate()方法截断该文件的大小。如果可选的尺寸参数存在,该文件被截断(最多)的大小。
大小默认为当前位置。当前文件位置不改变。注意,如果一个指定的大小超过了文件的当前大小,其结果是依赖于平台。
fileObject.truncate( [ size ])
参数
size -- 如果可选参数存在,文件被截断(最多)的大小。
返回值
此方法不返回任何值。
例子
#!/usr/bin/python # Open a file fo = open("foo.txt","rw+") print "Name of the file: ",fo.name # Assuming file has following 5 lines # This is 1st line # This is 2nd line # This is 3rd line # This is 4th line # This is 5th line line = fo.readline() print "Read Line: %s" % (line) # Now truncate remaining file. fo.truncate() # Try to read file Now line = fo.readline() print "Read Line: %s" % (line) # Close opend file fo.close()
当我们运行上面的程序,它会产生以下结果:
Name of the file: foo.txt Read Line: This is 1st line Read Line: