try / except

The basic shape

JavaScript:

try {
  doSomethingRisky();
} catch (error) {
  console.log('Something went wrong');
}

Python:

try:
    result = 10 / 0
except ZeroDivisionError:
    print("Cannot divide by zero")

except is Python's catch. The rest reads the same: code that might fail goes in the first block, recovery logic goes in the second.

A gotcha coming from JS: 10 / 0 in JavaScript doesn't throw — it quietly gives you Infinity. In Python, dividing by zero raises an exception. Different languages, different rules for what counts as an error.

Catch specific errors, not everything

JS's catch (error) catches anything, no questions asked. Python encourages you to name the specific exception type you expect, like ZeroDivisionError above. Common built-in ones you'll run into:

ZeroDivisionError   dividing by zero
ValueError          a value has the right type but a bad value (e.g. int("abc"))
KeyError            a dict key doesn't exist
IndexError           a list index is out of range
TypeError            an operation got the wrong type

You can still catch broadly with except Exception, and read the message via str(e) — similar to reading error.message in JS:

try:
    result = 10 / 0
except Exception as e:
    print(str(e))   # "division by zero"

Prefer naming the specific exception when you know what you're guarding against — it's the idiomatic Python style, and it stops you from accidentally swallowing an unrelated bug.

finally

Just like JS, finally always runs, whether or not an exception happened:

try:
    result = 10 / 0
except ZeroDivisionError:
    print("Cannot divide by zero")
finally:
    print("Done trying")