Lecture 43: Python has Un-changeable dic key

Nafees AI Lab

In Python, a dictionary stores data as key-value pairs. Each key within a dictionary must be unique and immutable, meaning it cannot be changed after it's created. Common data types used for keys include strings, numbers, and tuples

Transcript

00:00There is a small concept that I had to iterate on the definition, but I thought that you can clear that the dictionary's keys are immutable.

00:12The immutable data types of data types, you can replace them.

00:18For example, string is a immutable data type.

00:23You can replace it.

00:33This is a single pair of dictionary.

00:38You can replace it.

00:44If I run it, it's quite happy.

00:47The key is immutable.

00:57The key is immutable.

01:00The immutable data type is false.

01:04We have false.

01:06We see false.

01:09Nice.

01:10However, one thing we have noted is that the list is mutable.

01:15It is immutable.

01:16We have indexing and change the value.

01:19The list is equal to 1, 2, 3.

01:26One, two, three.

01:27So, I would say that the list of index is zero.

01:33I would not assign value to 2.

01:36I would say that.

01:37How was it possible?

01:39The list is immutable.

01:41I would say that the string is immutable.

01:45Basically, the dictionary is the key is immutable.

01:50Now, because the list is immutable,

01:52you can say that one of this list is equal to this thing.

01:57Now, I will run it.

01:59It's mad on me.

02:00Okay.

02:01It's a unhashable type.

02:05You cannot add this thing.

02:07Okay.

02:08Interesting.

02:09So, you can use any key, any data type except which is mutable.

02:19Which is mutable.

02:20The change is not.

02:21Okay.

02:22A small thing is to have to use which type is best.

02:29Of course, you will know what experience is.

02:32Which type is best.

02:36Imagine you have to develop a game.

02:38Now, we're in game today we have a player of countryاشita save.

02:46We're in this new movement,

02:47We,...

02:48Now, we have the list node the circle which � client.

02:50You can use characteristics...

02:51Characteristics.

02:52Ok.

02:53Carestan is ...

02:54Characteristics...

02:55א...

02:57Characteristics.

02:58And ...

02:59Characteristics is a name to have a group.

03:01Let's call...

03:02Let's say power,

03:05let's say power

03:07ठीक है और उसके पास

03:09let's say bonus है

03:11and so on

03:13however

03:14this is not

03:18the property

03:19is not the property तरीका exist

03:21करता है और वो

03:22basically इसको dictionary में आप define कर सकते है

03:25तो आप कहें dictionary

03:26ठीक है is equal to

03:28एक नई dictionary आप define करने लगा है

03:30उसकी खासित यह है

03:33कि आप उसमें कहते हैं player

03:34ठीक है, key is equal to, अब जरा आपने गवर करना है, player, और player करने हैं, let's say, john, या name, ठीक है, उसके साथ, power,

03:52full, अब देखिए, यह मज़ीद descriptive हो गया न, अब मैं, for example, मैं कहता हूँ, bonus, ठीक है,

04:08two lives, अब मज़ीद descriptive हो गया न, और अब मैं easily, जब भी dictionary की player के, let's say, power call करूंगा,

04:21तो मुझे उसका status देगा, कहेगा powerful, अजी, however, जो list है, उसके अंदर यह ऐसा descriptive नहीं है,

04:30यह एक छोटी सी example दिया है, कि कौन सी application के लिए कौन सा data structure बहतर है,

04:35तो आपने इस बात से, इस अवाले से mindful रहना है, कि list हो, यह dictionaries हो, यह application specific है,

04:44यह ऐसा नहीं है, कि dictionary अच्छी होती है list से, और list अच्छी होती है dictionary से,

04:49कोई list मारी, कोई list के साथ, यह तो नहीं है, को personal friendship है,

04:54basically, अगर हमने एक data structure को preference देनी है, on the other data structure, as a developer,

05:01तो हमें पता होना चाहिए, कि यह list application के लिए suitable है, ठीक है न, तो इस बात का दियान रखने,

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