Add CSV writing feature

README.md

@@ -1,7 +1,7 @@
 # CLI for First Data conversion rates
 
 ## Requirements
-* python3 with modules `PyPDF3`, `appdirs`, `mechanize`
+* python3 with modules `PyPDF3`, `appdirs`, `mechanize`, `dateutil`
 
 ## Usage:
 `python3 crawl.py [-t {VISA,MC}] [-g ISO_DATE] [-r] {-i | CURRENCY AMOUNT}`
@@ -10,6 +10,7 @@
 
 #### `AMOUNT` 
 This must be a number.
+
 #### `CURRENCY` 
 This must be the three-letter currency abbreviation, case is irrelevant.
 
@@ -22,16 +23,26 @@ Format: ISO date
 
 #### `-r`, `--direction`
 Reverse conversion direction (EUR to specified currency, instead of specified currency to EUR)
+
+#### `-c`, `--csv`
+Write the currency results to standard output, formatted as CSV:
+
+|ISO4217 abbreviation|Full German name|Asking rate|Bidding rate|Date the rate was valid on|
+|:---|:---|:---|:---|:---|
+
 #### `-i`, `--interactive`
 
 Calculate interactively on stdin
 
 ##### `q`, `exit`, `quit`
  Quit the program.
+
 ##### `AMOUNT CURRENCY`
  Convert AMOUNT euros to CURRENCY.
+
 ##### `CURRENCY AMOUNT`
  Convert AMOUNT CURRENCY to euros.
+
 ##### `d`, `date`
  Print the date the data is from.
 

crawl.py

@@ -8,6 +8,7 @@ import pathlib
 from datetime import date as DTDate
 from datetime import datetime as DTDateTime
 import appdirs
+import csv
 
 import utils
 
@@ -15,7 +16,7 @@ import utils
 DIRECTION_TO_EUR = 0
 DIRECTION_FROM_EUR = 1
 
-## Argument parsing
+# Argument parsing
 parser = argparse.ArgumentParser(
     description='Currency conversion using First Data cards.')
 parser.add_argument(
@@ -38,6 +39,12 @@ parser.add_argument(
     action='store_true',
     help='Reverse direction (EUR -> currency)'
 )
+parser.add_argument(
+    '-c', '--csv',
+    dest='csv',
+    action='store_true',
+    help='Write the results to stdout as CSV'
+)
 parser.add_argument(
     '--cache-dir',
     dest='cache_dir',
@@ -143,7 +150,8 @@ def calc_result(amt: float, rate: utils.Rate, direction: int, duty: float = 0) -
     elif direction == DIRECTION_TO_EUR:
         result = amt / rate.bid * 1+duty
     else:
-        raise ValueError('direction must be DIRECTION_FROM_EUR or DIRECTION_TO_EUR')
+        raise ValueError(
+            'direction must be DIRECTION_FROM_EUR or DIRECTION_TO_EUR')
     return result
 
 
@@ -159,6 +167,7 @@ def fmt_and_calc(amt: float, cur: str, res: utils.CurrencyResult, direction: str
     else:
         return 'Currency %s could not be found' % cur
 
+
 # args = parser.parse_args('USD 1000'.split())
 args = parser.parse_args()
 #logger = logging.getLogger('mechanize')
@@ -186,7 +195,8 @@ else:
 if args.cache_dir is not None:
     filepath = pathlib.Path(args.cache_dir).resolve()
 else:
-    filepath = pathlib.Path(appdirs.user_cache_dir('FirstDataCrawler', 'iwonder'))
+    filepath = pathlib.Path(appdirs.user_cache_dir(
+        'FirstDataCrawler', 'iwonder'))
 if not filepath.exists():
     filepath.mkdir(parents=True)
 filename = filepath / utils.mk_filename(retrieve_date, use_card_type)
@@ -209,5 +219,9 @@ if args.interactive:
             _process_stdin(input('> '), results)
     except (KeyboardInterrupt, EOFError):
         sys.exit()
+elif args.csv:
+    w = csv.writer(sys.stdout)
+    for rate in results.rates.values():
+        w.writerow([rate.abbr, rate.full_name, rate.ask, rate.bid, rate.date])
 else:
     print(fmt_and_calc(args.amt, args.currency, results, direction))

requirements.txt

@@ -1,3 +1,4 @@
 PyPDF3
 appdirs
 mechanize
+python-dateutil

utils.py

@@ -7,13 +7,15 @@ from collections import namedtuple
 from datetime import date as DTDate
 from datetime import timedelta as DTTimeDelta
 from datetime import datetime as DTDateTime
-from typing import BinaryIO, List
+from typing import BinaryIO, List, Dict
+from collections import OrderedDict
+from sys import stderr
 
 import mechanize as m
 import PyPDF3
 from dateutil.relativedelta import FR, relativedelta
 
-Rate = namedtuple('Rate', ['abbr', 'full_name', 'ask', 'bid'])
+Rate = namedtuple('Rate', ['abbr', 'full_name', 'ask', 'bid', 'date'])
 
 # Constants
 CARD_MASTERCARD = ['0']
@@ -22,7 +24,7 @@ CARD_VISA = ['1']
 
 class CurrencyResult:
     def __init__(self):
-        self.rates = list()
+        self.rates = Dict[str, Rate]
         self.card_type = str()
         self.date = None
 
@@ -63,7 +65,7 @@ def _array_remove_empty(obj: list) -> List[str]:
     return obj
 
 
-def _parse_line(line: str) -> Rate or None:
+def _parse_line(line: str, ctx: CurrencyResult) -> Rate or None:
     arr = line.split("   ") # 3 spaces = minimum separation in PDF
     arr = _array_remove_empty(arr)
     # process currency name
@@ -72,13 +74,14 @@ def _parse_line(line: str) -> Rate or None:
         abbr=names[0],
         full_name=names[1].strip("()"),
         ask=_parse_rate(arr[1]),
-        bid=_parse_rate(arr[2])
+        bid=_parse_rate(arr[2]),
+        date=ctx.date
         )
     return rate
 
 
 def get_results_from_text(text: str, currency: str = None) -> CurrencyResult:
-    rates = {}
+    rates = OrderedDict()
     result = CurrencyResult()
     lines = text.splitlines()
     # skip intro lines
@@ -92,25 +95,25 @@ def get_results_from_text(text: str, currency: str = None) -> CurrencyResult:
     # now the rates begin
     if currency is None:
         for line in lines:
-            line_result = _parse_line(line)
+            line_result = _parse_line(line, result)
             rates[line_result.abbr] = line_result
     else:
         pattern = re.compile("^"+currency)
         for line in lines:
             if pattern.match(line):
-                line_result = _parse_line(line)
+                line_result = _parse_line(line, result)
                 rates[line_result.abbr] = line_result
     result.rates = rates
     return result
 
 
 def get_results_from_pdf(buf: BinaryIO or str, currency: str = None) -> CurrencyResult:
-    print('Parsing data... ', end='')
+    print('Parsing data... ', end='', file=stderr)
     reader = PyPDF3.PdfFileReader(buf)
     text = str()
     for num in range(0, reader.getNumPages()-1):
         text += reader.getPage(num).extractText()
-    print('Done.')
+    print('Done.', file=stderr)
     return get_results_from_text(text, currency=currency)
 
 
@@ -164,3 +167,5 @@ def mk_filename(date: DTDate, card_type: List[str]) -> str:
     else:
         raise TypeError("not a valid card type")
     return fn
+
+