topic Re: gp.listfields Method in Python Questions

gp.listfields Method

DuncanRager — Tue, 08 Mar 2011 17:54:10 GMT

Greetings,

Basic question... I'm trying to list out the names of all the fields in a particular shapefile.

Using the gp.listfields method in the following manner...

fields = gp.listfields("[shapefile_location]")
print fields

...I get a list of items resembling, "geoprocessing describe field object object at 0x032A2F0".

How can I print the actual field names?

Thanks,

DR

Re: gp.listfields Method

JasonScheirer — Tue, 08 Mar 2011 18:04:50 GMT

print [f.name for f in fields]

Re: gp.listfields Method

DuncanRager — Tue, 08 Mar 2011 18:15:11 GMT

Worked great, thanks.

So I'm getting a 'u' in front of each field name... what does that mean?

Also, is this method specific to anything, like the geoprocessing object maybe? In other words, if I had a simple list, say...

silverware = ["forks", "knives", "spoons"]

...and I input...

print [f.name for f in silverware]

...I would get an error. What's the difference between the lists?

Thanks,

DR

Re: gp.listfields Method

DanPatterson_Retired — Sat, 11 Dec 2021 08:16:46 GMT

the u stands for unicode (just ignore it)

>>> silverware = ["forks", "knives", "spoons"]
>>> for utensil in silverware:
...  print utensil
...  
forks
knives
spoons

as for the "name" thing, your simple example above has no name property whereas a field has a name property as well as several others (eg type, precision, scale if appropriate etc etc)

Re: gp.listfields Method

JasonScheirer — Tue, 08 Mar 2011 18:32:32 GMT

u means it is a Unicode object, as opposed to a regular (locale-specific) C-style string.

Doing this:

print [f.name for f in silverware]

is trying to get the name property off the string, which does not exist, hence the error.