plot_mhz19.py: make temperature plot optional

diff --git a/plot_mhz19.py b/plot_mhz19.py
index 526c975d8f75fe91ec9db698768ee60151c2917c..4d3b90ab0b01e77a1348160cc7e3aef96e1c6512 100755 (executable)
--- a/plot_mhz19.py
+++ b/plot_mhz19.py
@@ -1,6 +1,7 @@
 #!/usr/bin/python3
 
 import csv
+import argparse
 from datetime import datetime, date, timedelta
 from matplotlib import pyplot as plt
 
@@ -16,28 +17,37 @@ def parsedatetime(timevalue, currentdate):
     dt = datetime.strptime(timevalue, '%H:%M:%S')
     return datetime.combine(currentdate, dt.time())
 
-with open(filename) as f:
-    reader = csv.reader(f)
-    headers = next(reader)
-
-    time = []
-    co2 = []
-    temp = []
-    startdate = date(2020, 10, 22)
-    for row in reader:
-        dt = parsedatetime(row[0], startdate)
-        if len(time) > 0 and dt - time[-1] < timedelta(hours=-2): # DST switch!
-            startdate += timedelta(days=1)
-            dt += timedelta(days=1)
-        time.append(dt)
-        co2.append(int(row[2]))
-        temp.append(int(row[3]))
-
-    plt.plot(time, co2, c = 'red')
-    plt.title('CO₂')
-    plt.xlabel('time')
-    plt.ylabel('ppm')
-    plt.tick_params(axis = 'both', which = 'major')
-    plt.gca().twinx()
-    plt.plot(time, temp, c = 'blue')
-    plt.show()
+def main():
+    parser = argparse.ArgumentParser('Plot log.csv.')
+    parser.add_argument('--temperature', '-t', action='store_true', help='Include temperature plot')
+    args = parser.parse_args()
+
+    with open(filename) as f:
+        reader = csv.reader(f)
+        headers = next(reader)
+
+        time = []
+        co2 = []
+        temp = []
+        startdate = date(2020, 10, 22)
+        for row in reader:
+            dt = parsedatetime(row[0], startdate)
+            if len(time) > 0 and dt - time[-1] < timedelta(hours=-2): # DST switch!
+                startdate += timedelta(days=1)
+                dt += timedelta(days=1)
+            time.append(dt)
+            co2.append(int(row[2]))
+            temp.append(int(row[3]))
+
+        plt.plot(time, co2, c = 'red')
+        plt.title('CO₂')
+        plt.xlabel('time')
+        plt.ylabel('ppm')
+        plt.tick_params(axis = 'both', which = 'major')
+        if args.temperature is True:
+            plt.gca().twinx()
+            plt.plot(time, temp, c = 'blue')
+        plt.show()
+
+if __name__ == '__main__':
+    main()