String Manipulation

Getting started with python and ArcGIS

Guido Steinguido@avidgeo.com

AvidGeo Meetup 2/21/2013

Guido Stein

● GIS AnalystApplied Geographics, Inc.○ Parcel Editing○ Extract, Transform, and Load○ Workflows

■ Model Builder■ Calculate Field■ Python

Overview

● Municipal Data● Variables● Fields● Strings As Lists● String Functions● More About String● Concatenation● Putting It Together● Single Line Statement If/Else● Next Time

It's Raining Data

Planimetric Data○ Road○ Building○ Fire Hydrant

Cadastral Data○ Municipal Boundaries○ Real Estate

■ Parcel■ Property

More Data More Problems

Parcel Polygon

045-267 / 88-3.A045-267/ 88-4045-267 / 88-5045- 267/88-6145- 267/88-7A145- 267/88-7B

Property Table

45-88-3-A45-88-445-88-545-88-6145-88-7A145-88-7B

String"guido"

Integer35

Float5.75

List["Burrito","Dorito"]

Variable Declarationme = "guido"age = 35height = 5.75sounds_like = ["Burrito","Dorito"]

Me, a name I call myself

Parseltongue Translator

VB

[parcel_id]

trim([parcel_id])

"N" & [parcel_id]

Python

!parcel_id!

!parcel_id!.strip()

"N" + !parcel_id!

Cutting the Cheese

cheese = "Gorgonzola"

["G","o","r","g","o","n","z","o","l","a"]

cheese[:4]"Gorg"● Like left() in VB

cheese[-4:]"zola"● Like right() in VB

cheese[4:-4]"on"● Like mid() in VB

Functional Design 1

● strip(), lstrip(), rstrip()● like VB trim()

par = "045-267 / 88-3.A"

par[:8]"045-267 "

par[:8].strip()"045-267"

par.lstrip("0")"45-267 / 88-3.A"

par.strip(" 0.3A-8/")"45-267"

Functional Design 2

● split()par = "045-267 / 88-3.A"

par.split('/')["045-267 "," 88-3.A"]

par.split('/')[0]"045-267 "

● replace()

par.replace('.','-')"045-267 / 88-3-A"

Now for something completely

different

Escape\New Line\nsingle/double quote\' \"

If you use single quote around string literal then double quotes don't need to be escaped

Vise versa

Concatenate

par = '045-267 / 88-3.A'

!par![1:3] + '-' + !par![4:7]'%s-%s' % (!par![1:3],!par![4:7])'45-267'

● %s - string● %i - integer● %.2f - float with 2 decimal points

Putting it together

par = '045-267 / 88-3.A'

'%s-%s' % (par[1:3],par.split('/')[1].replace('.','-').strip()

)

'45-88-3-A'

Putting it together for real

'%s-%s' % ( !parcel_id![1:3], !parcel_id!.split('/')[1].replace('.','-').strip())

More Data More Problems

Parcel Polygon

045-267 / 88-3.A045-267/ 88-4045-267 / 88-5045- 267/88-6145- 267/88-7A145- 267/88-7B

Property Table

45-88-3-A45-88-445-88-545-88-6145-88-7A145-88-7B

Putting it together for real, really

'%s-%s' % ( !parcel_id!.split('/')[0].strip(' 0'), !parcel_id!.split('/')[1].replace('.','-').strip())

Putting it together for real, really,

really

'%s-%s' % ( !parcel_id!.split('/')[0].strip(' 0').split('-')[0], !parcel_id!.split('/')[1].replace('.','-').strip())

One More thing

Null = None It will crash your statement

alternate statement if field is None else primary statement

'' if !parcel_id! is None else ('%s-%s' % ( !parcel_id!.split('/')[0].strip(' 0').split('-')[0], !parcel_id!.split('/')[1].replace('.','-').strip()))

Next Time

Advanced Calculate● building your own functions● tabbing● if,then, else, elif● import libraries

○ re● More string functions● variable comparison

String Manipulation

Getting started with python and ArcGIS

Guido Steinguido@avidgeo.com

AvidGeo Meetup 2/21/2013