Python File truncate() Method

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Description

The method truncate() truncates the file's size. If the optional size argument is present, the file is truncated to (at most) that size..

The size defaults to the current position. The current file position is not changed. Note that if a specified size exceeds the file's current size, the result is platform-dependent.

Note: This method would not work in case file is opened in read-only mode.

Syntax

Following is the syntax for truncate() method:

fileObject.truncate( [ size ])

Parameters

  • size -- If this optional argument is present, the file is truncated to (at most) that size.

Return Value

This method does not return any value.

Example

The following example shows the usage of truncate() method.

This is 1st line
This is 2nd line
This is 3rd line
This is 4th line
This is 5th line
#!/usr/bin/python

# Open a file
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

line = fo.readline()
print "Read Line: %s" % (line)

# Now truncate remaining file.
fo.truncate()

# Try to read file now
line = fo.readline()
print "Read Line: %s" % (line)

# Close opend file
fo.close()

When we run above program, it produces following result:

Name of the file:  foo.txt
Read Line: This is 1st line

Read Line:



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