Check users var

README.md

@@ -1,6 +1,14 @@
 ## Just a few GVA examples usage in python.
 
-Exemple:
+**Requierement**:
+```
+pip3 install --pre gql
+chmod u+x pay.py
+```
+
+### Usage exemple:
+
+**Send a payment**:
 ```
 ./pay.py Do99s6wQR2JLfhirPdpAERSjNbmjjECzGxHNJMiNKT3P 314 "Merci pour la pipe"
 ```

pay.py

@@ -1,11 +1,19 @@
 #!/usr/bin/env python3
 
-import sys
+import sys, os.path
+from shutil import copyfile
+if not os.path.isfile("userEnv.py"):
+  copyfile("userEnv.py.template", "userEnv.py")
+
 from userEnv import issuer, dunikey, node
 from natools import fmt, sign, get_privkey
 from gql import gql, Client
 from gql.transport.aiohttp import AIOHTTPTransport
 
+if not (issuer) or not (dunikey):
+  print("Please set your pubkey and path to you pubsec keychain in userEnv.py file.")
+  sys.exit(1)
+
 # Define Duniter GVA node
 transport = AIOHTTPTransport(url=node)
 client = Client(transport=transport, fetch_schema_from_transport=True)