Hi everyone .

Question

I have two problems here the first one: why does not keyerror’s except work here
despite of typing items which is not exsit
the second when I click control d nothing happens
and what the purpose of eof here?
https://www.sololearn.com/en/compiler-playground/cQk7Y03Eolnq

Answer 1

KeyError exception is not raised (triggered) because there is that `if` conditional at line 20 which prevents the attempt to refer a dictionary item from <menu> dictionary at line 21.

The `if` conditional at line 20 checks whether there is an item having <order> as its key in <menu> dictionary. If such item exists, its value will be added into <cost>. If you omit the check at line 20 and just go ahead try to accumulate the cost, you will have KeyError raised when <order> contains invalid key.

Where did you use "control d"? such key combination only works in real console interface. It won't work on SoloLearn.

Answer 2

Hello Yusof

Sorry for late reply, I didn't get the mention, I'm accessing SoloLearn from the web :)

Look here...

if order in menu:
cost += menu[order]

The `if` statement checks whether <menu> dictionary has any item whose key equals <order> variable value.

When <menu> dictionary has such item, the item's value will be added into <cost> variable.

When no match was found in <menu>, there will be no attempt to refer `menu[order]`, thanks to the check performed by `if` statement. Consequently, KeyError exception will not be raised.

* KeyError exception is raised when our code tries to refer a non-existing dictionary item (no item key matches the given key).

Answer 3

ThaksIpang actually I have tried the code on sololearn.
Do you mean if statement prevents
implementing key error's except.

Answer 4

Thanks no matters if you were let I appreciate