PYTHON
from urllib.parse import quote
GEO = ("country", "subdivision", "city", "zipcode")
LISTABLE = GEO + ("asn",)
ORDER = ("type",) + LISTABLE
DEVICE_TYPES = {"mobile", "common", "tv"}
def massive_username(base, **params):
"""Build a residential proxy username and enforce the documented list rules."""
unknown = set(params) - set(ORDER)
if unknown:
raise ValueError(f"unsupported keys: {sorted(unknown)}")
vals = {}
for key in ORDER:
value = params.get(key)
if value is None or value == "" or (
isinstance(value, (list, tuple)) and not value
):
continue
items = value if isinstance(value, (list, tuple)) else [value]
# The network ignores duplicate and empty values; drop them here too.
items = list(dict.fromkeys(str(v).strip() for v in items if str(v).strip()))
if key in LISTABLE and len(items) > 5:
raise ValueError(f"{key}: up to 5 values")
if key == "type" and not set(items) <= DEVICE_TYPES:
raise ValueError(f"type must be one of {sorted(DEVICE_TYPES)}")
vals[key] = items
if any(k in vals for k in GEO) and "country" not in vals:
raise ValueError("country is required with any geo key")
lists = [k for k in LISTABLE if len(vals.get(k, [])) > 1]
if len(lists) > 1:
raise ValueError(f"only one list per request, got {lists}")
if len(vals.get("country", [])) > 1 and any(k in vals for k in GEO[1:]):
raise ValueError("a list of countries can't be narrowed")
return "-".join([base] + [f"{k}-{','.join(quote(v) for v in vals[k])}" for k in vals])
print(massive_username("{PROXY_USERNAME}", country="US", city=["New York", "Chicago"]))
# {PROXY_USERNAME}-country-US-city-New%20York,Chicago