ArcPy – Creating a Layer from Python Dictionary Using ArcPy

arcmaparcpydictionary

I'm writing a script to find duplicate cables in a layer. I want to create a layer from the result to find the closest cables to those already cut with ArcPy but I can't find a way to do it.

The license I use is Standard so I don't have the FindIdentical_management function.

here is my code :

couche_cable = arcpy.MakeFeatureLayer_management(chem_caftth)
champ_a_verfier = ["REFERENCE", "OBJECTID", "CREATIONUSER", "LASTUSER", "USERREFERENCE", "SUBTYPEID", "SHAPE"]  
    values={}
    values["Ref_Nulle"]=0
    with arcpy.da.SearchCursor(couche_cable, champ_a_verfier) as rows:
        for r in rows:
            if r[0] in [None,""]:
                values["Ref_Nulle"]+=1
            else:
                if r[0] not in values:
                    values[r[0]]=1
                else:
                    values[r[0]]+=1 
    del rows
    
    
    dictDoublons = {}
    dictPasDoublons = {}
    cable_cda = 'CDA'
    count = 0
    for item in values:
        if values[item] > 1 and values[item] < 3:
            if not item.startswith("CDA"):
                dictDoublons[item] = 'Doublons'
                count+=1
                arcpy.AddWarning('Il y a {} cables en doublons  a Verifier / Corriger.'.format(count))
        else:   
            dictPasDoublons[item] = 'PasDoublons'

Best Answer

You can use a set:

import arcpy

fc = r'C:\GIS\ArcMap_default_folder\Default.gdb\my_sample'
fieldlist = ['kkod','kategori'] #Fields to consider for duplicates

values = set() #Create a set, which cant have duplicate values
oids = [] #A list to store object ids
for row in arcpy.da.SearchCursor(fc, ['OID@']+fieldlist):
    if row[1:] in values: #If the row values are in the set = they are a duplicate
        oids.append(row[0]) #Add the oid to oids list
    else:
        values.add(row[1:]) #If not add the values to the set

#Select the oids in oids list
oidfield = arcpy.Describe(fc).OIDFieldName
sql = """{0} IN{1}""".format(arcpy.AddFieldDelimiters(datasource=fc, field=oidfield), tuple(oids))
arcpy.SelectLayerByAttribute_management(in_layer_or_view='my_sample', where_clause=sql) #Or Select, MakeFeatureLayer etc.

Related Solutions

[GIS] Using ArcPy to Read from Excel Spreadsheet to Python Dictionary

Per other users suggestion, you should use Excel to Table GP tool with SearchCursor to construct the dictionary in python. Here is a sample code:

sample data in an excel file:

col1    col2    col3
---------------------
val1    val2    val3
val4    val5    val6


import arcpy

inputExcel = r"D:\Test.xls"
sheetName = "Sheet1"
memoryTable = "in_memory" + "\\" + "memoryTable"

#Make sure the memory is empty
arcpy.Delete_management(memoryTable)

arcpy.ExcelToTable_conversion(inputExcel, memoryTable,sheetName )


d = {}
fieldIndices = {}

fields = arcpy.ListFields(memoryTable)
for i,field in enumerate(fields):
    d[field.name]=[]
    fieldIndices[i] = field.name


with arcpy.da.SearchCursor(memoryTable, '*') as cursor:
    for row in cursor:
        for i in range(0,len(row)):
            d[fieldIndices[i]].append(row[i])

del cursor

And the output python dictionary:

>>> d
{u'ObjectID': [1, 2],
 u'col1': [u'val1', u'val4'],
 u'col2': [u'val2', u'val5'],
 u'col3': [u'val3', u'val6']}

I hope it helps

ArcPy – How to Create Arrays and Polylines from Dictionary

At first pass, I see two potential issues you might want to examine.

1) The rhino dictionary contains a list of what?

This line, coordPair = [coordX, coordY], says you want a list stored under each item in the rhino dictionary. I bet that works, but I tend to think of pairs as tuples. So try changing the line to:

coordPair = (coordX, coordY)

This says, here's a tuple of X and Y, but we really want the dictionary to store a list, so let's change this bit as well:

def rhinoTrackFinder(rhino, coordX, coordY, dictionary):
    if rhino not in dictionary:
        dictionary[rhino] = []
    dictionary[rhino].append((coordX, coordY))

Note, I removed the coordPair assignment and just append the tuple directly.

So now rhinoTrackFinder will create a dictionary, keyed by rhino, containing a list of tuples.

rhinoTrackDictionary['bob'] might contain: (1,1), (2,4), (-3,7). These tuples should make it easier to read later.

2) What are lon and lat being assigned to?

Further along, you have lon = CoordX and lat = CoordY. Python loves global variables, so from what I can tell, you are just setting lon and lat to the last row values from the csvReader, CoordX = row [XCoordIndex] and CoordY = row [YCoordIndex]. That's probably not right.

If we use that tuple stuff above, try:

for rhino in rhinoTrackDictionary:
    for coord in rhinoTrackDictionary[rhino]:
        lon = coord[0]
        lat = coord[1]
        print rhino, lon, lat
        ...

We're going from rhino to rhino, and looking at the list of coordinates for that rhino. Then we go coordinate to coordinate.

For each coordinate, looks like you're adding it to the VertexArray, which then you use to create your polyline. That should all work.

Best Answer

Related Solutions

[GIS] Using ArcPy to Read from Excel Spreadsheet to Python Dictionary

ArcPy – How to Create Arrays and Polylines from Dictionary

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