Python 3 File write()用法及代码示例

描述

方法write()将字符串 str 写入文件。没有返回值。由于缓冲，在调用 flush() 或 close() 方法之前，该字符串可能实际上不会出现在文件中。

用法

以下是语法write()方法 -

fileObject.write( str )

参数

str- 这是要写入文件的字符串。

返回值

此方法不返回任何值。

示例

下面的例子展示了 write() 方法的用法。

Assuming that 'foo.txt' file contains following text:
This is 1st line
This is 2nd line
This is 3rd line
This is 4th line
This is 5th line

#!/usr/bin/python3

# Open a file in read/write mode
fo = open("abc.txt", "r+")
print ("Name of the file:", fo.name)

str = "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 = next(fo)
      print ("Line No %d - %s" % (index, line))

# Close opened file
fo.close()

结果

当我们运行上述程序时，它会产生以下结果 -

Name of the file: foo.txt

Line No 0 - This is 1st line
Line No 1 - This is 2nd line
Line No 2 - This is 3rd line
Line No 3 - This is 4th line
Line No 4 - This is 5th line
Line No 5 - This is 6th line