Re: Import syntax question
- To: mathgroup at smc.vnet.net
- Subject: [mg85556] Re: Import syntax question
- From: Mark Fisher <particlefilter at gmail.com>
- Date: Wed, 13 Feb 2008 07:13:14 -0500 (EST)
- References: <200802101022.FAA18017@smc.vnet.net> <foucgt$l35$1@smc.vnet.net>
On Feb 13, 4:16 am, "Igor C. Antonio" <ig... at wolf-ram.com> wrote:
> Hi Mark,
>
> You should do:
>
> Import["file.pdf", {{"Author", "Title"}}] or
>
> Import["file.pdf", {"PDF", {"Author", "Title"}].
>
> The general syntaxes for extracting elements are:
>
> Import["file", {"format", "elem1"}]
> ---> import elem1 of "file" imported as "format."
>
> Import["file", {"format", "elem1", "subelem1", ...}]
> ---> When elem1 is itself a list of elements, you can import its "subelements."
> This one means import the subelem1 of elem1 (when elem1 is a list of rules) of
> the "file" imported as "format."
>
> Import["file", {"format", {"elem1", "elem2", "elem3"...}}]
> ---> This is the syntax for importing multiple elements.
>
> To make things a little more confusing ;), there's a shorthand notation when the
> second argument is *only one string*: You can omit the {}'s:
>
> Import["file.pdf", "Author"]
> Import["file.pdf", "Title"]
>
> Import uses FileFormat[] for format detection if you don't explicitly specify
> the "format," but the {}'s must remain as shown above if your second argument
> contains more than one string.
>
> Igor
>
> --
> Igor C. Antonio
> Wolfram Research, Inc.http://www.wolfram.com
>
> To email me personally, remove the dash.
>
> Mark Fisher wrote:
> > Hi all,
>
> > I find Import wonderful but frustrating. For example, I can get
> > individual items such as "Author" and "Title" in separate calls:
>
> > Import["file.pdf", "Author"]
> > Import["file.pdf", "Title"]
>
> > but I can't get a list as in
>
> > Import["file.pdf", {"Author", "Title"}]
>
> > Instead I get an error message that say "Title" is not present (which
> > seems misleading at best, since I already accessed it above). Is that
> > syntax supposed to work or not? (Frankly, I'm having a hard time
> > figuring out what the proper generic syntax is for Import, especially
> > since there are so few examples in the documentation.)
>
> > BTW, I found out I can use
>
> > {"Author", "Title"} /. Import["file.pdf", "Rules"]
>
> > Is that what I "should" be doing? (It seems like overkill since Import
> > has to import a bunch more stuff that I don't want, at least in this
> > example.)
>
> > --Mark
Thank you for your clear exposition.
--Mark
- References:
- Import syntax question
- From: Mark Fisher <particlefilter@gmail.com>
- Import syntax question