Included a cache

.gitignore

@@ -1 +1,2 @@
 __pycache__
+cache.json

meuro.py

@@ -1,11 +1,24 @@
 #!/usr/bin/python3
-import requests
+import requests, json, os.path
 from datetime import datetime
 from dateutil import relativedelta
 from dateutil import parser as dparser
 from dateutil.parser._parser import ParserError as DateParserError
 
-# Ugly code thats outside of any function
+_years = None
+
+def _loadYearsTable(maxCacheSeconds=3600):
+    if os.path.isfile('cache.json'):
+        with open('cache.json', 'r') as f:
+            cacheUpdate, cacheYears = json.loads(f.read())
+        if (datetime.now() - dparser.isoparse(cacheUpdate)).total_seconds() < maxCacheSeconds:
+            # JSON does not allow integers as keys; so we convert them back here...
+            cacheYears = {int(y):{int(m):float(n) for m,n in ms.items()} for y,ms in cacheYears.items()}
+            return cacheYears
+    return _loadYearsTableWeb()
+
+def _loadYearsTableWeb():
+    print('[i] Fetching new data from ECB-Servers...')
     url = 'https://sdw.ecb.europa.eu/quickviewexport.do?SERIES_KEY=122.ICP.M.U2.N.000000.4.ANR&type=csv'
     resp = requests.get(url)
     lines = resp.text.split('\n')[6:]
@@ -24,11 +37,17 @@ for year in years:
         for month in range(1,13):
             if month not in months:
                 years[year][month] = 1 + 0.02/12 # Lets say the ECB archives their target
+    with open('cache.json', 'w') as f:
+        f.write(json.dumps([datetime.now().isoformat(),years]))
+    return years
 
 # Gives you the exchange rate between euros and meuros for the given date.
 # (Should always be a float < 1)
 # date should be either a datetime-object or None (= current date)
 def exchangeRate(date=None):
+    global _years
+    if _years==None:
+        _years = _loadYearsTable()
     if date==None:
         date = datetime.now()
     month, year = date.month, date.year
@@ -37,23 +56,24 @@ def exchangeRate(date=None):
     akk = 1
     for fullYear in range(2001, year):
         yearlyInf = 1
-        for m in years[fullYear]:
+        for m in _years[fullYear]:
-            monthlyInf = years[fullYear][m]
+            monthlyInf = _years[fullYear][m]
             yearlyInf *= monthlyInf
         akk *= yearlyInf
 
     for fullMonth in range(1, month):
-        monthlyInf = years[year][fullMonth]
+        monthlyInf = _years[year][fullMonth]
         akk *= monthlyInf
 
     beginningOfMonth = date.replace(hour=0, minute=0, second=0, microsecond=0, day=1)
     endOfMonth = beginningOfMonth + relativedelta.relativedelta(months=1)
     fracOfMonth = (date - beginningOfMonth).total_seconds() / (endOfMonth - beginningOfMonth).total_seconds()
-    inflationThisMonth = 1 + fracOfMonth * (years[year][month]-1)
+    inflationThisMonth = 1 + fracOfMonth * (_years[year][month]-1)
 
     akk *= inflationThisMonth
 
     return 1/akk
+
 # Converts the given amount of euros to meuros for the given date. (wholeCents means it rounds to two decimal places)
 # date should be either a datetime-object or None (= current date)
 def euroToMeuro(eur,date=None,wholeCents=True):