topic Read dbf with arcpy in PyCharm? in Esri Labs Questions

Read dbf with arcpy in PyCharm?

AaqibJamshed — Sun, 14 Nov 2021 06:46:41 GMT

I have exported an ArcGIS Desktop 10.7 table into a dbf file.
Now I want to do some GIS calculation in standalone Python.
Therefore I have started a PyCharm project referencing the ArcGIS Python interpreter and hence am able to import arcpy into my main.py.
Problem is: I don't want to pip install other modules, but I don't know how to correctly read the dbf table with arcpy.

#encoding=utf-8 
import arcpy
path=r"D:\test.dbf"
sc=arcpy.SearchCursor(path) # Does not work: IOError exception str() failed
tv=arcpy.mapping.TableView(path) # Does not work either: StandaloneObject invalid data source or table

The dbf file is correct, it can be read into ArcGIS.
Can someone please give me an idea, how to read the file standalone with arcpy?

Re: Read dbf with arcpy in PyCharm?

DanPatterson — Sun, 14 Nov 2021 10:24:59 GMT

path=r"D:\test.dbf"

Is in the root directory, try putting it into a folder

path=r"D:\TestData\test.dbf"

Also, arcpy.da cursors

SearchCursor—ArcGIS Pro | Documentation

And you need to specify the fields to use (field_names) they are not optional. you only specified the file, and not the fields, so it will fail

SearchCursor (in_table, field_names, {where_clause}, {spatial_reference}, {explode_to_points}, {sql_clause}, {datum_transformation})

Re: Read dbf with arcpy in PyCharm?

Salenley — Sat, 22 Jan 2022 09:55:17 GMT

Using Pandas

Python from ArcMap comes with some modules. You can load the data into a pandas.DataFrame and work with this format. Pandas is well-documented and there is a lot of already asked question about it all over the web. It's also super easy to do groupby or table manipulations.

import pandas as pd
import arcpy


def read_arcpy_table(self, table, fields='*', null_value=None):
    """
    Transform a table from ArcMap into a pandas.DataFrame object

    table : Path the table
    fields : Fields to load - '*' loads all fields
    null_value : choose a value to replace null values
    """
    fields_type = {f.name: f.type for f in arcpy.ListFields(table)}
    if fields == '*':
        fields = fields_type.keys()
    fields = [f.name for f in arcpy.ListFields(table) if f.name in fields]
    fields = [f for f in fields if f in fields_type and fields_type[f] != 'Geometry'] # Remove Geometry field if FeatureClass to avoid bug

    # Transform in pd.Dataframe
    np_array = arcpy.da.FeatureClassToNumPyArray(in_table=table,
                                                 field_names=fields,
                                                 skip_nulls=False,
                                                 null_value=null_value)
    df = self.DataFrame(np_array)
    return df
# Add the function into the loaded pandas module
pd.read_arcpy_table = types.MethodType(read_arcpy_table, pd)

df = pd.read_arcpy_table(table='path_to_your_table')
# Do whatever calculations need to be done

Using CURSOR

You can also use arcpy cursors and dict for simple calculation.

There are simple example on this page on how to use correctly cursors : https://desktop.arcgis.com/fr/arcmap/10.3/analyze/arcpy-data-access/searchcursor-class.htm l