[Tutor] Mysql BLOB strangeness?
Hugo González Monteverde
hugonz-lists at h-lab.net
Mon Mar 20 05:40:34 CET 2006
> However, there is still a learning point that might be missed here -
> how does Python grab BLOB data-types, and how do you manipulate them?
> If it were a file, would you just be able to grab the file without the
The basic issue is: what form is used for representing arbitrary byte
data of arbitrary length.
1) strings: strings in python are arbitrarily large and can store
any byte values (compare this with other languages like C where the
number 0 signals the end of a string) Strings are OK, and that's what
the standard library writes to files.
2) arrays: there is but one problem with strings, and that they are
inmutable: you have to create a new string everytime you want to change
an old one. Long data chunks are inefficiently worked when using
strings, so you may use arrays (array.array) which can be changed in place.
Of course there are many more options, like a tuple or a list of 255 or
less ints, but these are the main contenders for byte valued sequences.
Hope that clears thing a bit,
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