Python 3 - 文件 write() 方法

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  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，字符串可能不会真正显示在文件中。
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  句法

  以下是语法write()方法 -

  
  fileObject.write( str )
  

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  参数

  str− 这是要写入文件的字符串。
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  返回值

  此方法不返回任何值。
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  例子

  以下示例显示了 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()
  

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  结果

  当我们运行上面的程序时，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