Python in a Nutshell

Name

load, loads

Synopsis

load(fileobj)
loads(str)

loads creates and returns the object v previously dumped to string str, so that, for any object v of a supported type, v equals loads(dumps( v )). If str is longer than dumps( v ), loads ignores the extra bytes. load reads the right number of bytes from file object fileobj, which must be opened for reading in binary mode, and creates and returns the object v represented by those bytes. fileobj cannot be a file-like object: it must be an instance of type file.

Functions load and dump are complementary. In other words, a sequence of calls to load( f ) deserializes the same values previously serialized when f’s contents were created by a sequence of calls to dump( v,f ). Objects that are dumped and loaded in this way can be instances of any mix of supported types.

Suppose you need to analyze several text files, whose names are given as your program’s arguments, and record where each word appears in those files. The data you need to record for each word is a list of ( filename, line-number ) pairs. The following example uses marshal to encode lists of ( filename, line-number ) pairs as strings and store them in a DBM-like file (as covered later in this chapter). Since those lists contain tuples, each made up of a string and a number, they are within marshal’s abilities to serialize.

import fileinput, marshal, anydbm wordPos = { } for line in fileinput.input( ): pos = fileinput.filename( ), fileinput.filelineno( ) for word in line.split( ...