topic format field in Python Questions

format field

2Quiker — Sat, 11 Dec 2021 15:42:31 GMT

Trying to format a field but I am not sure how accomplish it. The trouble I am having is the making the second to last 0 a space but only if there is no alph char. WellPin field is always 10 numbers and sometimes with an alph char. Can someone help me out by showing me how to do this with updatecurosr and in a filed calculator please?

Well WPin

W1234500000 --> 12345000 0

W1234501000--> 12345010 0

W12345010S0--> 12345010S0

W12345010S1--> 12345010S1

Here what I have so far.

import arcpy

arcpy.env.overwriteOutput = True
fc = r"C:\Temp\Wells.shp"
count = 0

def maketv_cursor(fc):  
   
    rows = arcpy.SearchCursor(table,"WPin")  
    count = 0  
    for row in rows:  
        count += 1 

#print(count)
with arcpy.da.UpdateCursor(fc,['WellID','WPin']) as cursor:  
    for row in cursor: #if row[0] in (None, "", " "):
        row [1] = (row[0][1:11]) # Field Calculator!WellID! [1:11]
        cursor.updateRow(row)‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: format field

RandyBurton — Sat, 11 Dec 2021 15:42:34 GMT

A quick example (using underscore for space):

rows = [['W1234500000',],
        ['W1234501000',],
        ['W12345010S0',],
        ['W12345010S1',] ]

for row in rows:
    if row[0][10] == '0':
        print(row[0][:9]+"_"+row[0][-1:])
    else:
        print(row[0])

prints:
W12345000_0
W12345010_0
W12345010_0
W12345010S1‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: format field

DanPatterson — Sat, 11 Dec 2021 15:42:37 GMT

w0 = "W1234500000"
w1 = "W12345010S0"

import string
nums = string.digits

def conv(fld, nums):
    """docstring"""
    if fld[-2] in nums:
        return "{} {}".format(fld[1:-2], fld[-1:])
    else:
        return fld[1:]
        

conv(w0, nums)
'12345000 0'

conv(w1, nums)
'12345010S0'
‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: format field

2Quiker — Sat, 11 Dec 2021 15:42:39 GMT

I am getting error string index out of range on line 5.

Also the "_" to " " because i need the space not the underscore.

dict = {r[0]:(r[1:]) for r in arcpy.da.SearchCursor(fc,['WellID','WPin'])}

with arcpy.da.UpdateCursor(fc,['WellID','WPin']) as cursor: 
    for row in cursor:
        if row[0][10] == '0':
            #print(row[0][:9]+"_"+row[0][-1:])
            row [1] = row[0][:9]+" "+row[0][-1:]
        else:
            print(row[0])
        cursor.updateRow(row)‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: format field

2Quiker — Fri, 28 Aug 2020 20:38:17 GMT

I am kind of lost on this one because it's not formatted with updatecusror, can you explain what's going on please?

Re: format field

DanPatterson — Fri, 28 Aug 2020 21:18:10 GMT

Use the Calculate Field or the just the field calculator. I see little reason to use a search cursor on this.

besides, your 'row' is my 'fld' and I use a different means of slicing that relies less on string length but more on string head/tail positions of the things to change. I am sure you will see upon closer examination

Re: format field

JoshuaBixby — Sat, 11 Dec 2021 15:42:42 GMT

If it has to be an update cursor, try:

import arcpy

fc = r"C:\Temp\Wells.shp"

with arcpy.da.UpdateCursor(fc,['WellID','WPin']) as cursor:  
    for wellid, wpin in cursor:
        if wellid not in (None, "", " "):
            i,j,k = wellid[:-2], wellid[-2], wellid[-1:]
            wpin = "{}{}{}".format(i, j if not j.isdigit() else " ", k)
            cursor.updateRow([wellid, wpin])‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: format field

RandyBurton — Sat, 29 Aug 2020 04:39:00 GMT

Joshua Bixby‌ If the goal is to keep the letter and drop the zero from the next to last position, shouldn't line 9 be ("not" isdigit) ?

wpin = "{}{}{}".format(i, j if not j.isdigit() else " ", k)‍

Re: format field

JoshuaBixby — Mon, 31 Aug 2020 14:16:19 GMT

Randy Burton‌, good catch, I got mixed up on what the OP was after. You are correct, I have updated my code snippet. Thanks.

Re: format field

2Quiker — Sat, 11 Dec 2021 15:42:45 GMT

I am getting error 000989. If and else have two indent and the return have 4 indents.

Field Calculator

import string
nums = string.digits

def conv( WellID , nums):
    """docstring"""
  if !WellID! [-2] in nums: # two space indents
    return "{} {}".format( !WellID! [1:-2], !WellID! [-1:])#four spaces indents
  else: # two space indents
    return !WellID! [1:]‍‍‍‍‍‍‍‍‍#four spaces indents‍‍‍‍‍‍‍‍‍

Code Block

def conv( WellID , nums)‍

Re: format field

DanPatterson — Mon, 31 Aug 2020 17:49:49 GMT

indent it properly then, like in my example

Re: format field

2Quiker — Mon, 31 Aug 2020 20:12:37 GMT

I have but for some reason it won't work no matter how many spaces(indents) I put in, in line 6 gives me the same error.

Re: format field

JoshuaBixby — Mon, 31 Aug 2020 20:27:53 GMT

One problem you have is with your variable names. You don't put the field name in exclamations in the function definition. For example, don't do !WellID! and instead do WellID.

Re: format field

2Quiker — Mon, 31 Aug 2020 20:52:00 GMT

This worked, although would it be best to do just do it through Calculate field management.

Re: format field

DanPatterson — Sat, 11 Dec 2021 15:42:47 GMT

import string
nums = string.digits

def conv( WellID , nums):
    """docstring"""
    if !WellID! [-2] in nums: # two space indents
        return "{} {}".format( !WellID! [1:-2], !WellID! [-1:])#four spaces indents
    else: # two space indents
        return !WellID! [1:]#four spaces indents‍‍‍‍‍‍‍‍‍

Re: format field

2Quiker — Mon, 31 Aug 2020 20:57:32 GMT

After your suggestion I am getting error 000539 invalid syntax expression line 1.

Re: format field

JoshuaBixby — Sat, 11 Dec 2021 15:42:50 GMT

Looking at your screenshot from earlier, you are also trying to define a function in the expression box.

Your expression should be:

conv(!WellID!)‍

and your pre-script code should be:

import string
nums = string.digits

def conv(WellID):
    """docstring"""
  if WellID[-2] in nums:
    return "{} {}".format(WellID[1:-2], WellID[-1:])
  else:
    return WellID[1:]‍‍‍‍‍‍‍‍‍