Ruby equivalent for Python's "try"?
I'm trying to convert some Python code into Ruby. Is there an equivalent in Ruby to the try
statement in Python?
Solution 1:
Use this as an example:
begin # "try" block
puts 'I am before the raise.'
raise 'An error has occurred.' # optionally: `raise Exception, "message"`
puts 'I am after the raise.' # won't be executed
rescue # optionally: `rescue Exception => ex`
puts 'I am rescued.'
ensure # will always get executed
puts 'Always gets executed.'
end
The equivalent code in Python would be:
try: # try block
print('I am before the raise.')
raise Exception('An error has occurred.') # throw an exception
print('I am after the raise.') # won't be executed
except: # optionally: `except Exception as ex:`
print('I am rescued.')
finally: # will always get executed
print('Always gets executed.')
Solution 2:
begin
some_code
rescue
handle_error
ensure
this_code_is_always_executed
end
Details: http://crodrigues.com/try-catch-finally-equivalent-in-ruby/
Solution 3:
If you want to catch a particular type of exception, use:
begin
# Code
rescue ErrorClass
# Handle Error
ensure
# Optional block for code that is always executed
end
This approach is preferable to a bare "rescue" block as "rescue" with no arguments will catch a StandardError or any child class thereof, including NameError and TypeError.
Here is an example:
begin
raise "Error"
rescue RuntimeError
puts "Runtime error encountered and rescued."
end