Python中操作文件之write()方法的使用教程

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 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：

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