This content originally appeared on DEV Community and was authored by Aatmaj
Today we are going to solve some questions related to dictionaries. ? So in case you have missed yesterday's blog where we have covered dictionaries in depth, click here.
Just a bit of revision of dictionaries which we covered yesterday.
Defination-
A dictionary is defined as a general-purpose data structure for storing a group of objects. A dictionary is associated with a set of keys and each key has a single associated value.
Dictionaries are used for retrieving a value from a key
In dictionaries, the keys are mapped with specific values. They are somewhat similer to hashtables. we will cover hashtables in tomorrow's part, but today we will first take a closer look at how dictionaries operate by solving some questions related to them.
Sample program 1
Let's see how to fuse two separate lists into a key-value pair dictionary.
a=["a","b","c","d"]#list -key
b=(1,2,3,4)#tuple- value
#Method 1
c={} #empty dictionary
for i in range(0,len(a)):
c[i]=a[i]
print(c)
#Method 2
d=dict(zip(a,b))
print(d)
In the above program, we have fused the keys(list a) and the values(tuple b) into a dictionary(c and d ). In the second method, we have used two methods dict() and zip(). The dict() method is used to create a dictionary while the zip method is used to zip together two key-value pairs.
Sample question 2)
Write code to make this dictionary using for loop-
{0: 0, 1: 2, 2: 4, 3: 6, 4: 8, 5: 10, 6: 12, 7: 14, 8: 16, 9: 18}
Solution-
a={}
for i in range(0,10):
a[i]=2* i
print(a)
Exercise 1) Modify the above code to give the following output-
{'d': 16, 'c': 9, 'a': 1, 'b': 4}
(Don't mind the order)
Sample question 3) Write a program for making the dictionary shown below using for loops-
a={
1: [1, 2, 3, 4, 5],
2: [2, 3, 4, 5, 6],
3: [3, 4, 5, 6, 7],
4: [4, 5, 6, 7, 8],
5: [5, 6, 7, 8, 9]
}
Solution-
a={}
for i in range(1,6):
a[i]=[]
for j in range(i,i+5):
a[i].append(j)
print(a)
OUTPUT-
{1: [1, 2, 3, 4, 5], 2: [2, 3, 4, 5, 6], 3: [3, 4, 5, 6, 7], 4: [4, 5, 6, 7, 8], 5: [5, 6, 7, 8, 9]}
Exercise 2)- Modify the above program for making the following dictionary-
b={
1:[1],
2:[1,2],
3:[1,2,3],
4:[1,2,3,4],
5:[1,2,3,4,5]
}
Answers to the above exercise will be found as usual in the Learning-Python Repository
Fun exercise
Can you find the levels of nesting? first one is solved for you. Answer in the comments below!?
a={[([1,2,3])]:[[{1:2}]]}
#key: List in a tuple in a list value: dictionary in a list in a list.
b={[1,2]:(((1,2,3)))}
c={1:[([(1,2,3)])]
d={[({[1,2]:[(1,2,3)]})]:[((1,2,{2:3}))]}#invalid... Can you find out why?
e=[[(a,b),c]:(d,(a))]
✌️So friends that's all for now. ? Hope you all are having fun.? Please let me know in the comment section below ?. And don't forget to like the post if you did. ? I am open to any suggestions or doubts. ? Just post in the comments below or gmail me. ?
Thank you all?
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This content originally appeared on DEV Community and was authored by Aatmaj
Aatmaj | Sciencx (2021-07-21T04:13:04+00:00) Learning Python-Basic course: Day 19, Practicing Dictionary exercises. Retrieved from https://www.scien.cx/2021/07/21/learning-python-basic-course-day-19-practicing-dictionary-exercises/
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