Python中操作文件之write()方法的使用教程

时间:2022-08-29 11:00:55

 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:

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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。

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#!/usr/bin/python
 
# Open a file in write mode
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
 
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 = fo.next()
  print "Line No %d - %s" % (index, line)
 
# Close opend file
fo.close()

当我们运行上面的程序,它会产生以下结果:

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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