use with-statement for open()

main.py

@@ -35,9 +35,8 @@ def check_connection():
         time.sleep(3)
         if not wlan_sta.isconnected():
             # inside passwd file, there is a list of WiFi networks (CSV format)
-            f = open("passwd.dat")
+            with open("passwd.dat") as f:
                 data = f.readlines()
-            f.close()
             # Search WiFis in range
             ssids_found = wlan_sta.scan()
 

networkconfig.py

@@ -106,17 +106,14 @@ def handle_configure(client, request):
 		<br><br>"""
         send_response(client, response_footer)
         try:
-            fo = open("passwd.dat", "r")
+            with open("passwd.dat", "r") as fo:
                 ex_data = fo.read()
-            fo.close()
-            fo = open("passwd.dat", "w")
             ex_data = ssid + ";" + password + "\n" + ex_data
+            with open("passwd.dat", "w") as fo:
                 fo.write(ex_data)
-            fo.close()
         except:
-            fo = open("passwd.dat", "w")
+            with open("passwd.dat", "w") as fo:
                 fo.write(ssid + ";" + password + "\n")
-            fo.close()
         return True
     else:
         response_footer = """