add default values

app.py

@@ -56,6 +56,8 @@ def predict(mseeds=[], waveforms="", stations=""):
         waveforms = np.array(waveforms)
         print(f"{waveforms.shape = }")
     picks = []
+    if mseeds is None:
+        mseeds = []
     for mseed in mseeds:
         file = mseed.name  # if not isinstance(input, str) else input
         mseed = obspy.read(file)
@@ -83,7 +85,7 @@ def predict(mseeds=[], waveforms="", stations=""):
 
         picks.extend(tmp_picks)
 
-    if len(picks) > 0
+    if len(picks) > 0:
         picks_df = pd.DataFrame(picks)
         picks_df.to_csv("picks.csv", index=False)
     else: