Reading .csv file with Python and DictReader missing columns

Question

I have the following .csv file I’m trying to read as a whole:

---------------------------------------------------------------
#INFO            |           |        |       |        |      |
---------------------------------------------------------------
#Study name      | g1        |        |       |        |      |
---------------------------------------------------------------
#Respondent Name | name      |        |       |        |      |
---------------------------------------------------------------
#Respondent Age  | 20        |        |       |        |      |
---------------------------------------------------------------
#DATA            |           |        |       |        |      |
---------------------------------------------------------------
Row              | Timestamp | Source | Event | Sample | Anger|
---------------------------------------------------------------
1                | 133       | Face   | 1     | 3      | 0.44 |
---------------------------------------------------------------
2                | 240       | Face   | 1     | 4      | 0.20 |
---------------------------------------------------------------
3                | 12        | Face   | 1     | 5      | 0.13 |
---------------------------------------------------------------
4                | 133       | Face   | 1     | 6      | 0.75 |
---------------------------------------------------------------
5                | 87        | Face   | 1     | 7      | 0.25 |
---------------------------------------------------------------

Image of the file

This is the code I am using to open, read the file, and print to the terminal:

import csv

def read_csv():
    with open("in/2.csv", encoding="utf-8-sig") as f:
        reader = csv.DictReader(f)
        print(list(reader))
read_csv()

The output I am getting includes only the first two columns of my .csv:

[{'#INFO': '#Study name', '': ''}, {'#INFO': '#Respondent Name', '': ''}, {'#INFO': '#Respondent Age', '': ''}, {'#INFO': '#DATA', '': ''}, {'#INFO': 'Row', '': 'Anger'}, {'#INFO': '1', '': '4.40E-01'}, {'#INFO': '2', '': '2.00E-01'}, {'#INFO': '3', '': '1.30E-01'}, {'#INFO': '4', '': '7.50E-01'}, {'#INFO': '5', '': '2.50E-01'}]

Why are the other columns missing from my output? I want the other columns starting from Row to be included as well. Any direction would be appreciated. Thanks!

Asked By: ChenBr

||

Source

Answer 1

Try:

for _ in zip(f, range(5)): 
    pass

before initializing DictReader. This should skip the first 5 lines.

import csv

def read_csv():
    with open("in/2.csv", encoding="utf-8-sig") as f:
        for _ in zip(f, range(5)): 
            pass
        reader = csv.DictReader(f)
        print(list(reader))
read_csv()

Answered By: Yevhen Kuzmovych

Answer 2

The DictReader expects a file where the first row contains column names (each name different from each other) and following rows contain data entries. If multiple column names are just empty strings, the value in the last column is assigned to key '' in the returned dictionary.

To skip the first five lines instead, you can write:

import csv

def read_csv():
    with open("in/2.csv", encoding="utf-8-sig") as f:
        for _ in range(5):
            next(f)

        reader = csv.DictReader(f)
        print(list(reader))
read_csv()

Answered By: Michael Butscher

Reading .csv file with Python and DictReader missing columns

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