﻿ Python: Flatten a shallow list - w3resource

# Python: Flatten a shallow list

## Python List: Exercise - 23 with Solution

Write a Python program to flatten a shallow list.

Example - 1 : Example - 2 : Example - 3 : Sample Solution-1:

Python Code:

``````import itertools
original_list = [[2,4,3],[1,5,6], , [7,9,0]]
new_merged_list = list(itertools.chain(*original_list))
print(new_merged_list)
```
```

Sample Output:

```[2, 4, 3, 1, 5, 6, 9, 7, 9, 0]
```

## Visualize Python code execution:

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

Sample Solution-2:

Use a list comprehension to extract each value from sub-lists in order.

Python Code:

``````def flatten(nums):
return [x for y in nums for x in y]
nums = [[1, 2, 3, 4], [5, 6, 7, 8]]
print("Original list elements:")
print(nums)
print("\nFlatten the said list:")
print(flatten(nums))
nums = [[2,4,3],[1,5,6], , [7,9,0]]
print("\nOriginal list elements:")
print(nums)
print("\nFlatten the said list:")
print(flatten(nums))
```
```

Sample Output:

```Original list elements:
[[1, 2, 3, 4], [5, 6, 7, 8]]

Flatten the said list:
[1, 2, 3, 4, 5, 6, 7, 8]

Original list elements:
[[2, 4, 3], [1, 5, 6], , [7, 9, 0]]

Flatten the said list:
[2, 4, 3, 1, 5, 6, 9, 7, 9, 0]
```

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

Given a predicate function, fn, and a prop string, this curried function will then take an object to inspect by calling the property and passing it to the predicate:

Example:

```def tips_check_prop(fn, prop):
return lambda obj: fn(obj[prop])
check_age = tips_check_prop(lambda x: x >= 25, 'age')
user = {'name': 'Owen', 'age': 25}

print(check_age(user))
```

Output:

```True
```

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