try / except / else / finally

Pendahuluan

try/except Dasar

try:
    x = int('abc')
except ValueError:
    print('not a number')

Menangkap Objek Pengecualian

try:
    int('oops')
except ValueError as e:
    print(f'Error: {e}')

Menangkap Beberapa Pengecualian

for val in ['abc', None, 42]:
    try:
        print(int(val))
    except (TypeError, ValueError) as e:
        print(f'skipping {val!r}: {e}')

except Tanpa Tipe (hindari)

try:
    risky = 1/0
except ZeroDivisionError:
    print('division error')  # specific

Beberapa Klausa except

def process(val):
    try:
        return 10 / int(val)
    except ValueError:
        print('not a number')
    except ZeroDivisionError:
        print('division by zero')
process('abc')
process('0')

Klausa else

try:
    x = int('42')
except ValueError:
    print('bad input')
else:
    print('parsed:', x)

Klausa finally

def read_file(path):
    f = None
    try:
        f = open(path)
        return f.read()
    except FileNotFoundError:
        return None
    finally:
        if f: f.close()
print(read_file('/nonexistent'))

finally dengan return

def demo():
    try:
        return 'try'
    finally:
        return 'finally'  # overrides!
print(demo())

Blok try Bertingkat

try:
    try:
        x = 1/0
    except ValueError:
        print('inner')
except ZeroDivisionError:
    print('outer caught it')

Mencatat Pengecualian

import logging
try:
    1/0
except ZeroDivisionError:
    logging.exception('Caught an error')

Pemeriksaan Singkat

Ringkasan

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