Load csv file in processing.py

Question

I am trying to load a csv file in processing.py as a table. The Java environment allows me to use the loadTable() function, however, I'm unable to find an equivalent function in the python environment.

Does using the standard python library to read CSV's not work for your use-case? https://docs.python.org/2/library/csv.html — justderb, Apr 18 '17 at 06:17
[try this](http://stackoverflow.com/questions/3518778/how-to-read-csv-into-record-array-in-numpy) — R.A.Munna, Apr 18 '17 at 06:19
Processing.py looks to have `loadTable` now: https://github.com/jdf/processing.py/blob/7c30e038600c221c5b70590a50160d918b5dd86b/mode/examples/Topics/AdvancedData/LoadSaveTable/LoadSaveTable.pyde#L44 — justderb, Apr 18 '17 at 06:21

score 0 · Answer 1 · answered Apr 18 '17 at 07:30

The missing functionality could be added as follows:

import csv

class Row(object):
    def __init__(self, dict_row):
        self.dict_row = dict_row

    def getFloat(self, key):
        return float(self.dict_row[key])

    def getString(self, key):
        return self.dict_row[key]

class loadTable(object):
    def __init__(self, csv_filename, header):
        with open(csv_filename, "rb") as f_input:
            csv_input = csv.DictReader(f_input)
            self.data = [Row(row) for row in csv_input]

    def rows(self):
        return self.data

This reads the csv file into memory using Python's csv.DictReader class. This treats each row in the csv file as a dictionary. For each row, it creates an instance of a Row class which then lets you retrieve entries in the format required. Currently I have just coded for getFloat() and getString() (which is the default format for all csv values).

villares · Answer 2 · 2021-05-01T23:35:29.183

You could create an empty Table object with this:

from processing.data import Table
t = Table()

And then populate it as discussed at https://discourse.processing.org/t/creating-an-empty-table-object-in-python-mode-and-some-other-hidden-data-classes/25121

But I think a Python Dict as proposed by @martin-evans would be nice. You load it like this:

import csv
from codecs import open # optional to have the 'enconding="utf-8"' in Python 2

with open("data/pokemon.csv", encoding="utf-8") as f:
    data = list(csv.DictReader(f))  # a list of dicts, col-headers as keys

Load csv file in processing.py

2 Answers2