write()方法把字符串str写入文件。没有返回值。由于缓冲，字符串可能不实际显示文件，直到flush()或close()方法被调用。
语法

以下是write()方法的语法：

fileObject.write( str )

参数

• str -- 这是要被写入的文件中的字符串。

返回值

此方法不返回任何值。
例子

下面的例子显示write()方法的使用。

#!/usr/bin/python# Open a file in write modefo = 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 linestr = "This is 6th line"# Write a line at the end of the file.fo.seek(0, 2)line = fo.write( str )# Now read complete file from beginning.fo.seek(0,0)for index in range(6): line = fo.next() print "Line No %d - %s" % (index, line)# Close opend filefo.close()

当我们运行上面的程序，它会产生以下结果：

Name of the file: foo.txtLine No 0 - This is 1st lineLine No 1 - This is 2nd lineLine No 2 - This is 3rd lineLine No 3 - This is 4th lineLine No 4 - This is 5th lineLine No 5 - This is 6th line