fix most "scripts"

related: #4754

electrum/scripts/block_headers.py

@@ -3,29 +3,33 @@
 # A simple script that connects to a server and displays block headers
 
 import time
-import sys
+import asyncio
 
-from .. import SimpleConfig, Network
-from electrum.util import print_msg, json_encode
+from electrum.network import Network
+from electrum.util import print_msg, json_encode, create_and_start_event_loop, log_exceptions
 
 # start network
-c = SimpleConfig()
-network = Network(c)
+loop, stopping_fut, loop_thread = create_and_start_event_loop()
+network = Network()
 network.start()
 
 # wait until connected
-while network.is_connecting():
-    time.sleep(0.1)
+while not network.is_connected():
+    time.sleep(1)
+    print_msg("waiting for network to get connected...")
 
-if not network.is_connected():
-    print_msg("daemon is not connected")
-    sys.exit(1)
+header_queue = asyncio.Queue()
+
+@log_exceptions
+async def f():
+    try:
+        await network.interface.session.subscribe('blockchain.headers.subscribe', [], header_queue)
+        # 3. wait for results
+        while network.is_connected():
+            header = await header_queue.get()
+            print_msg(json_encode(header))
+    finally:
+        stopping_fut.set_result(1)
 
 # 2. send the subscription
-callback = lambda response: print_msg(json_encode(response.get('result')))
-network.send([('server.version',["block_headers script", "1.2"])], callback)
-network.subscribe_to_headers(callback)
-
-# 3. wait for results
-while network.is_connected():
-    time.sleep(1)
+asyncio.run_coroutine_threadsafe(f(), loop)