Add 'mhl_waverider.py'

mhl_waverider/mhl_waverider.py

@@ -0,0 +1,39 @@
+"""Download lateset time series data from MHL website and update local copy.
+D. Howe
+2019-08-30
+"""
+import os
+import pandas as pd
+
+# Set output directory
+output_dir = 'csv'
+
+# Define data URLs
+url = 'http://www.mhl.nsw.gov.au/data/realtime/timeseries/'
+txt_names = [
+    'SYDDOW.WaveHeight.csv.dat.txt',
+    'SYDDOW.WavePeriod.csv.dat.txt',
+]
+
+for txt_name in txt_names:
+    # Read text file from MHL website
+    df = pd.read_csv(url + txt_name, index_col=0, parse_dates=True)
+
+    # Create name for exported data
+    csv_name = os.path.join(input_dir, txt_name.replace('.dat.txt', ''))
+    try:
+        # Load local master table
+        master = pd.read_csv(csv_name, index_col=0, parse_dates=True)
+
+        # Only include timestamps that do not already exist
+        df = df[~df.index.isin(master.index)]
+
+        # Update master
+        master = master.append(df)
+
+    except FileNotFoundError:
+        # Create new master table if none exists
+        master = df
+
+    # Export master table
+    master.to_csv(csv_name)