Updated March 29, 2023
Introduction to Python 3 has_key
The following article provides an outline for Python 3 has_key. In python dict, more specifically, the dictionary is a very important data type. The dict item allows the python to set up a large amount of capability for data processing. Dict being an unordered collection of items there is always a necessity to check whether an item is there or not. This means the python dict, which is made up of values and keys, expects to have a specific key in it, and there will be a need to check and confirm whether the particular key is present or not. This can be checked using the has_key method. The has_key method checks a dictionary item and identifies whether a particular key is present. This is the key advantage of python has_keys.
Syntax:
Dictionary_name.has_key(dictionary key)The key elements of has key are as below; first, the dictionary name has to be considered. This is the most important element. So as the dictionary name is considered, then the method which is opted for is discussed. The method, in this case, is the has_key method. So this is a critical element to be considered. Finally, whatever item to be encapsulated has to be mentioned within the has key method. So the key value which is going to be targeted will be placed within the has_key method. as a summary, the dictionary name and the has key element along with the dictionary key are the key elements in the python has_key method from the syntaxial declaration perspective.
How has_key works?
The process of how the has key method works is discussed here. As mentioned in the introduction section, the has key method intends to set the Boolean value based on the presence of one specific key in the dictionary. This means the has_key method works in such a way that when a given key is declared as a part of the dictionary item, then that key being identified will be returned true by the has key method, whereas when the key is not available, then it will return false. So the expectation here is when the key value is present, then true will be returned by the has a key method; in the other case, when the key is not available in the targeted dictionary, then false will be declared. This is how the has key method works in python applications. The has key method is specially related to the python 3 versions of python. So determining the presence of one particular key can be sophisticatedly identified with the help of these has key methods.
Examples of Python 3 has_key
Different examples are mentioned below:
Example #1
Code:
Dictionary_item = { 'A': 'hello', 'B': 'world' }
# Dictionary to be checked
print("Dictionary to be checked: ")
print(Dictionary_item )
# Use of has_key() to check
# for presence of a key in Dictionary
print(Dictionary_item.has_key('A'))
print(Dictionary_item.has_key('For'))Output:
Explanation:
The first example involves the below process; the process involves a declaration of a dictionary. So a dictionary has to be declared first. This is the dictionary on which the has key method is expected to be executed. So this is the first and critical step. The process of how the has key method works is discussed here. As mentioned in the introduction section, the has key method intends to set the Boolean value based on the presence of one specific key in the dictionary. This means the has_key method works in such a way that when a given key is declared as a part of the dictionary item then that key being identified will be returned true by the has key method, whereas when the key is not available, then it will return false.
Next, the dictionary is printed onto the console. This is the next major aspect to be considered. This process involves getting the dictionary item that is currently being discussed in the console output for reference. After the dictionary is printed in the console next the has key executions have to take place. In the case of this example, the execution is done in two different ways. The ways include the process of first checking the Presence of a specific key in the dictionary; then the next step involves when the key which is not associated as a part of the dictionary is mentioned. This second step is also a key factor to check the negative condition. So we can notice from the output derived that a true value is presented for a key that is associated as a part of the dictionary.
Example #2
Code:
Dictionary_item = { 'A': 'Good', 'B': 'Morning' }
# Dictionary to be checked
print("Dictionary to be checked: ")
print(Dictionary_item )
# Use of has_key() to check
# for presence of a key in Dictionary
print(Dictionary_item.has_key('A'))
print(Dictionary_item.has_key('For'))Output:
Explanation:
The second example is also very closely related to the first item; the key difference here is the values and keys used in the dictionary. So there is a key change in the dictionary item which is discussed. This is how the has keywords in the dictionary. As mentioned above, here to the values printed onto the console. This is the next major aspect to be considered. This process involves getting the dictionary item that is currently being discussed in the console output for reference. After the dictionary is printed in the console next the has key executions have to take place. In the case of this example, the execution is done in two different ways. The ways include the process of first checking the Presence of a specific key in the dictionary; then the next step involves when the key which is not associated as a part of the dictionary is mentioned. This second step is also a key factor to check the negative condition.
Conclusion – Python 3 has_key
The article clearly explains how to use has a key method in python and what is the use of has key method. Along with this, it also explains the ways and syntaxial methods of using has a key method in python.
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