Have a list, need a DataFrame to use `loc` to lookup rows by column values

Question

I'm trying to pull out the rows from these CSVs where the state is "Pennsylvania": https://github.com/CSSEGISandData/COVID-19/tree/master/csse_covid_19_data/csse_covid_19_daily_reports_us

I have this code:

import glob
import pandas as pd

df = []

path = "/home/reallymemorable/Documents/git/COVID-19/csse_covid_19_data/csse_covid_19_daily_reports_us/*.csv"
for fname in glob.glob(path):
    row = df.loc[df['Province_State'] == 'Pennsylvania']
    print(row)

I'm getting this error:

AttributeError: 'list' object has no attribute 'loc'

I understand that it's expecting a DataFrame but I've set df as a list. But I don't know how to make it a DataFrame so that my pattern matching works correctly.

What am I doing wrong?

Quang Hoang · Accepted Answer · 2020-11-12 21:23:28Z

1

In your code, df is the empty list [] that you define at the beginning, not a Pandas DataFrame. Did you forget to load the data:

path = "/home/reallymemorable/Documents/git/COVID-19/csse_covid_19_data/csse_covid_19_daily_reports_us/*.csv"
for fname in glob.glob(path):
    df = pd.read_csv(fname)   # this line???
    row = df.loc[df['Province_State'] == 'Pennsylvania']
    print(row)

answered Nov 12, 2020 at 21:23

Quang Hoang

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1 Comment

reallymemorable Over a year ago

...Is it obvious that I haven't used Python in a while?

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