reading_simple_refactor.py

import os

csv_directory = "CSVs"
signals_search = ["temperatura", "otracosa"]
missing_signals_file = {}

for csv_file in os.listdir(csv_directory):
    with open("{}/{}".format(csv_directory, csv_file)) as file_csv:
        header = file_csv.readline()
        missing_signals_file[csv_file] = [signal for signal in signals_search if signal not in header]

for key, value in missing_signals_file.items():
    print (key, value)

Gracias brother