Read CSV items with column name

Question

When reading a CSV, instead of skipping the first line (header), and reading row items by number:

with open('info.csv') as f:
    reader = csv.reader(f, delimiter=';')
    next(reader, None)
    for row in reader:
        name = row[0]
        blah = row[1]

is there a built-in way to access row items by making use of the header line? Something like:

with open('info.csv') as f:
    reader = csv.reader(f, delimiter=';', useheader=True)
    for row in reader:
        name = row['name']
        blah = row['blah']

where info.csv has a header line:

name;blah
John;Hello2
Mike;Hello2

Asked By: Basj

||

Source

Answer 1

Yes, there is. That’s what csv.DictReader function does – supplies the rows as an iterable of dicts.

Answered By: Moses Koledoye

Answer 2

You are looking for DictReader

with open('info.csv') as f:
    reader = csv.DictReader(f, delimiter=';')
    for row in reader:
        name = row['name']
        blah = row['blah']

to quote from the link:

Create an object which operates like a regular reader but maps the
information read into a dict whose keys are given by the optional
fieldnames parameter.
…
If the fieldnames parameter is omitted, the values in the first row of
the csvfile will be used as the fieldnames.

Answered By: e4c5

Answer 3

You can use a csv.DictReader instance to get this behaviour.

Example from the docs:

>>> with open('names.csv', newline='') as csvfile:
...     reader = csv.DictReader(csvfile)
...     for row in reader:
...         print(row['first_name'], row['last_name'])
...
Eric Idle
John Cleese

The reader generates the dictionary keys from the first row of the csv file automatically. If the csv file does not contain a header row you can set the keys by passing a list to the DictReader:

fieldnames = ['first_name', 'last_name']
reader = csv.DictReader(csvfile, fieldnames=fieldnames)

Answered By: snakecharmerb

Read CSV items with column name

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