Multiple try codes in one block
I have a problem with my code in the try block. To make it easy this is my code:
try:
code a
code b #if b fails, it should ignore, and go to c.
code c #if c fails, go to d
code d
except:
pass
Is something like this possible?
You'll have to make this separate try
blocks:
try:
code a
except ExplicitException:
pass
try:
code b
except ExplicitException:
try:
code c
except ExplicitException:
try:
code d
except ExplicitException:
pass
This assumes you want to run code c
only if code b
failed.
If you need to run code c
regardless, you need to put the try
blocks one after the other:
try:
code a
except ExplicitException:
pass
try:
code b
except ExplicitException:
pass
try:
code c
except ExplicitException:
pass
try:
code d
except ExplicitException:
pass
I'm using except ExplicitException
here because it is never a good practice to blindly ignore all exceptions. You'll be ignoring MemoryError
, KeyboardInterrupt
and SystemExit
as well otherwise, which you normally do not want to ignore or intercept without some kind of re-raise or conscious reason for handling those.
You can use fuckit module.
Wrap your code in a function with @fuckit
decorator:
@fuckit
def func():
code a
code b #if b fails, it should ignore, and go to c.
code c #if c fails, go to d
code d
Extract (refactor) your statements. And use the magic of and
and or
to decide when to short-circuit.
def a():
try: # a code
except: pass # or raise
else: return True
def b():
try: # b code
except: pass # or raise
else: return True
def c():
try: # c code
except: pass # or raise
else: return True
def d():
try: # d code
except: pass # or raise
else: return True
def main():
try:
a() and b() or c() or d()
except:
pass
If you don't want to chain (a huge number of) try-except clauses, you may try your codes in a loop and break upon 1st success.
Example with codes which can be put into functions:
for code in (
lambda: a / b,
lambda: a / (b + 1),
lambda: a / (b + 2),
):
try: print(code())
except Exception as ev: continue
break
else:
print("it failed: %s" % ev)
Example with arbitrary codes (statements) directly in the current scope:
for i in 2, 1, 0:
try:
if i == 2: print(a / b)
elif i == 1: print(a / (b + 1))
elif i == 0: print(a / (b + 2))
break
except Exception as ev:
if i:
continue
print("it failed: %s" % ev)