Láimhsítear earráidí i Python le bloic try/except, agus roghanna else agus finally ar fáil. Gealladh Python an phrionsabal EAFP — "Easier to Ask Forgiveness than Permission" — i bhféachaint ar an oibríocht a thriail agus eisceachtaí a láimhseáil seachas coinníollacha a sheiceáil ar dtús.
try:
result = risky_operation()
except ValueError as e: # catch a SPECIFIC exception type
print(f"bad value: {e}")
except (KeyError, IndexError): # catch multiple types
print("lookup failed")
except Exception as e: # catch-all (use sparingly, last)
print(f"unexpected: {e}")
else:
print("ran only if NO exception occurred")
finally:
cleanup() # ALWAYS runs (success or failure)
except SpecificError — glacadh le cineálacha sonracha (is fearr ná gealadh faoi leith).else — ritheonn ach amháin mura raibh eisceachta curtha in iúl.finally — ritheann i gcónaí (glantachán, foinse a scaoileadh), fiú má scaipeann eisceachta.# LBYL ("Look Before You Leap") — check first
if key in my_dict:
value = my_dict[key]
# EAFP ("Easier to Ask Forgiveness") — try it, handle failure — more Pythonic
try:
value = my_dict[key]
except KeyError:
value = default
Soláthraítear idiomatic Python go bhféachann EAFP — iarracht an oibríochta agus an eisceachta a ghabháil — a sheachaint rachadh agus is minic níos geal ná réamhseiceáil.
if amount < 0:
raise ValueError("amount must be positive") # raise a built-in
class InsufficientFundsError(Exception): # custom exception type
pass
raise InsufficientFundsError("balance too low")
# ❌ bare except hides bugs (catches EVERYTHING, even typos/KeyboardInterrupt)
try: ...
except: pass
# ✅ catch specific exceptions; re-raise what you can't handle
try: ...
except ValueError as e:
logger.error(e)
raise # re-raise to propagate
✓ Catch SPECIFIC exceptions, not bare except
✓ Don't silently swallow errors (except: pass) — log or handle them
✓ Use finally / context managers (with) for cleanup
✓ Raise meaningful, specific exception types
Tá láimhseáil earráidí ródhlúth riachtanach do chláir iontaofa, agus tá idiom ar leith ag dóigh Python: an struchtúr try/except/else/finally, an fhealsúnacht EAFP (triail-agus-láimhseáil seachat-seiceáil-ar-dtús, atá níos Pythonic agus a sheachanaíonn coinníollacha rása), eisceachtaí sonracha a ghabháil (ní bhare except, a bhíonn ag folaigh botúin), agus finally/context managers a úsáid do ghlanadh.
Túiscint ar na nithe seo a chur ar chúl ionsaí ó earráidí neamhláimhsíochta agus na fadhbanna dolbhéimnithe doranna a bhaineann le láimhseáil róbhreise nó gan fuaim eisceachtaí — foinse minic de chód neamhiontaofa.