029FileOperations.py

# READING A FILE
with open("welcome.txt") as text_file:
  text_data = text_file.read()
print(text_data)

# READING LINES
with open("how_many_lines.txt") as lines_doc:
  for line in lines_doc.readlines():
    print(line)
    
# READING A LINE
with open("just_the_first.txt") as first_line_doc:
  first_line = first_line_doc.readline()
print(first_line)

# WRITING A FILE
with open("bad_bands.txt", "w") as bad_bands_doc:
  bad_bands_doc.write("4Me")
  
# APPENDING TO A FILE
with open("cool_dogs.txt", "a") as cool_dogs_file:
  cool_dogs_file.write("Air Buddy")
  
# READING A CSV FILE
import csv
with open("cool_csv.csv") as cool_csv_file:
  cool_csv_dict = csv.DictReader(cool_csv_file)
  for row in cool_csv_dict:
    print(row)
    
# READING DIFFERENT TYPES OF CSV FILES
import csv
with open('books.csv') as books_csv:
  books_reader = csv.DictReader(books_csv, delimiter='@')
  isbn_list = [book['ISBN'] for book in books_reader]
print(isbn_list)

# WRITING A CSV FILE
access_log = [{'time': '08:39:37', 'limit': 844404, 'address': '1.227.124.181'}, {'time': '13:13:35', 'limit': 543871, 'address': '198.51.139.193'}, {'time': '19:40:45', 'limit': 3021, 'address': '172.1.254.208'}, {'time': '18:57:16', 'limit': 67031769, 'address': '172.58.247.219'}, {'time': '21:17:13', 'limit': 9083, 'address': '124.144.20.113'}, {'time': '23:34:17', 'limit': 65913, 'address': '203.236.149.220'}, {'time': '13:58:05', 'limit': 1541474, 'address': '192.52.206.76'}, {'time': '10:52:00', 'limit': 11465607, 'address': '104.47.149.93'}, {'time': '14:56:12', 'limit': 109, 'address': '192.31.185.7'}, {'time': '18:56:35', 'limit': 6207, 'address': '2.228.164.197'}]
fields = ['time', 'address', 'limit']

import csv
with open("logger.csv", "w") as logger_csv:
  log_writer = csv.DictWriter(logger_csv, fieldnames = fields)
  log_writer.writeheader()
  for item in access_log:
    log_writer.writerow(item)

# READING A JSON FILE
import json
with open("message.json") as message_json:
  message = json.load(message_json)
  print(message["text"])
 
# WRITING A JSON FILE
data_payload = [
  {'interesting message': 'What is JSON? A web application\'s little pile of secrets.',
   'follow up': 'But enough talk!'}
]
import json
with open("data.json","w") as data_json:
  json.dump(data_payload,data_json)