Finding first key-value pair from a Dictionary in Python
In this article, we will see of different methods by which we can fetch the first key-value pair of a dictionary. We will also discuss how to get first N pairs and any number of key-value pairs from a dictionary.
Getting first key-value pair of dictionary in python using iter() & next() :
In python, iter() function creates a iterator object of the the iterable sequence of key-value pairs from dictionary and by calling next() function we can get the first key-value pair.
# Program :
dict_eg = {
'Sachin' : 10,
"Gayle" : 333,
'Kohil' : 18,
'Murali' : 800,
'Dhoni' : 7,
'AB' : 17
}
# Get the first key-value pair in dictionary
dict_eg = next(iter((dict_eg.items())) )
print('The first Key Value Pair in the Dictionary is:')
print(dict_eg)
print('First Key: ', dict_eg[0])
print('First Value: ', dict_eg[1])
Output :
The first Key Value Pair in the Dictionary is:
('Sachin', 10)
First Key:Â Sachin
First Value:Â 10Get first key-value pair of dictionary using list :
In python, items() function in dictionary returns the iterable sequence of all key-value pairs. Then by creating a list from all key-value pairs in dictionary and by selecting the first item we will get first key-value pair of dictionary.
# Program :
dict_eg = {
'Sachin' : 10,
"Gayle" : 333,
'Kohil' : 18,
'Murali' : 800,
'Dhoni' : 7,
'AB' : 17
}
# Get the first key-value pair in dictionary
dict_eg = list(dict_eg.items())[0]
print('First Key Value Pair of Dictionary:')
print(dict_eg)
print('Key: ', dict_eg[0])
print('Value: ', dict_eg[1])
Output :
First Key Value Pair of Dictionary:
('Sachin', 10)
Key:Â Sachin
Value:Â 10Getting the first N key-value pair of dictionary in python using list & slicing :
Here from similar process, we will create a list of key-value pairs from dictionary. We can get first ‘N’ items by list[:N] or any items by list[start:end].
# Program :
dict_eg = {
'Sachin' : 10,
"Gayle" : 333,
'AB' : 17,
'Murali' : 800,
'Dhoni' : 7,
'AB' : 17,
'Kohil' : 18
}
n = 5
# Get first 5 pairs of key-value pairs
firstN_pairs = list(dict_eg.items())[:n]
print('The first 5 Key Value Pairs of Dictionary are:')
for key,value in firstN_pairs:
print(key, '::', value)
Output : The first 5 Key Value Pairs of Dictionary are: Dhoni :: 7 Kohil :: 18 Gayle :: 333 Sachin :: 10 AB :: 17
Getting the first N key-value pair of dictionary in python using itertools :
We can slice first ‘N’ entries from a sequence by itertools.islice(iterable, stop) after creating key-value pairs sequence from items() function.
# Program :
import itertools
dict_eg = {
'Sachin' : 10,
"Gayle" : 333,
'AB' : 17,
'Murali' : 800,
'Dhoni' : 7,
'AB' : 17,
'Kohil' : 18
}
n = 5
# Get first 5 pairs of key-value pairs
firstN_pairs = itertools.islice(dict_eg.items(), n)
print('The first 5 Key Value Pairs of Dictionary are:')
for key,value in firstN_pairs:
print(key, '::', value)
Output : The first 5 Key Value Pairs of Dictionary are: Murali :: 800 AB :: 17 Sachin :: 10 Dhoni :: 7 Kohil :: 18