﻿ Python: Select a random element from a list, set, dictionary and a file from a directory - w3resource

# Python: Select a random element from a list, set, dictionary and a file from a directory

## Python module: Exercise-2 with Solution

Write a Python program to select a random element from a list, set, dictionary-value, and file from a directory.

Use random.choice

Sample Solution:

Python Code:

``````import random
import os
print("Select a random element from a list:")
elements = [1, 2, 3, 4, 5]
print(random.choice(elements))
print(random.choice(elements))
print(random.choice(elements))
print("\nSelect a random element from a set:")
elements = set([1, 2, 3, 4, 5])
# convert to tuple because sets are invalid inputs
print(random.choice(tuple(elements)))
print(random.choice(tuple(elements)))
print(random.choice(tuple(elements)))
print("\nSelect a random value from a dictionary:")
d = {"a": 1, "b": 2, "c": 3, "d": 4, "e": 5}
key = random.choice(list(d))
print(d[key])
key = random.choice(list(d))
print(d[key])
key = random.choice(list(d))
print(d[key])
print("\nSelect a random file from a directory.:")
print(random.choice(os.listdir("/")))
```
```

Sample Output:

```Select a random element from a list:
3
4
5

Select a random element from a set:
1
3
5

Select a random value from a dictionary:
5
4
4

Select a random file from a directory.:
proc
```

Flowchart: ## Visualize Python code execution:

The following tool visualize what the computer is doing step-by-step as it executes the said program:

Python Code Editor:

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## Python: Tips of the Day

Inverts a dictionary with non-unique hashable values:

Example:

```def tips_collect_dictionary(obj):
inv_obj = {}
for key, value in obj.items():
inv_obj.setdefault(value, list()).append(key)
return inv_obj
ages = {
"Owen": 25,
"Jhon": 25,
"Pepe": 15,
}
print(tips_collect_dictionary(ages))
```

Output:

```{25: ['Owen', 'Jhon'], 15: ['Pepe']}
```

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