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