uses dotenv to store api key and other important variables

if a value is not found in .env it will be prompted, but not checked
next step is user docs

src/APIHandler.py

@@ -1,4 +1,5 @@
 import os, requests
+from dotenv import load_dotenv
 from getpass import getpass
 import elabapi_python as elabapi
 
@@ -20,10 +21,13 @@ class APIHandler:
     """
 
     # TO-DO: remove static url.
-    def __init__(
-        self, api_key="", ELABFTW_API_URL="https://elabftw.fisica.unina.it/api/v2"
-    ):
+    def __init__(self, api_key="", ELABFTW_API_URL=None):
         """Init method, api_key suggested but not required (empty by default)."""
+        if not ELABFTW_API_URL:
+            load_dotenv()
+            ELABFTW_API_URL = os.getenv("ELABFTW_API_URL") or input(
+                "Enter a valid eLabFTW API URL (ends with '/api/v2)': "
+            )
         self.api_key = api_key
         self.auth = {"Authorization": api_key}
         self.content = {"Content-Type": "application/json"}

src/main.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 import os, json, requests, h5py
 import numpy as np
-import dotenv
+from dotenv import load_dotenv
 from getpass import getpass
 from APIHandler import APIHandler
 from classes import *
@@ -91,7 +91,7 @@ def call_layers_from_list(elabid_list):
                 + str(e)
                 + f"\nPlease solve the problem before retrying."
                 + "\n\n"
-                + f"Last resource attempted to call: {ELABFTW_API_URL}/experiments/{elabid}"
+                + f"Last resource attempted to call at base url: /experiments/{elabid}"
             )
     return list_of_layers  # list of Layer-class objects
 
@@ -870,15 +870,18 @@ def build_nexus_file(pld_fabrication, output_path="output/nffa-di_unnamed.h5"):
 
 
 if __name__ == "__main__":
-    # TO-DO: place the API base URL somewhere else.
-    ELABFTW_API_URL = "https://elabftw.fisica.unina.it/api/v2"
-    api_key = getpass("Paste API key here: ")
-    elabid = input("Enter elabid of your starting sample [default = 1111]: ") or 1111
+    load_dotenv()
+    api_key = os.getenv("api_key") or getpass("Paste API key here: ")
+    elabid = (
+        os.getenv("elabid")
+        or input("Enter elabid of your starting sample [default = 1111]: ")
+        or 1111
+    )
     handler = APIHandler(api_key)
     data = handler.get_entry_from_elabid(elabid)
     sample = Entrypoint(data)
     sample_name = sample.name.strip().replace(" ", "_")
-    operative_unit = "Napoli"
+    operative_unit = os.getenv("operative_unit") or None
     if sample.proposal:
         sample_proposal = call_proposal_from_elabid(sample.proposal)
     else:
@@ -890,7 +893,7 @@ if __name__ == "__main__":
     fn_base = (
         "nffa-di_"
         + (f"{sample_proposal}_" if sample_proposal else "")
-        + operative_unit
+        + (f"{operative_unit}_" if operative_unit else "")
         + "_"
         + sample_name
     )