﻿ Python: A valid filename - w3resource

# Python: A valid filename

## Python Programming Puzzles: Exercise-59 with Solution

A valid filename should end in .txt, .exe, .jpg, .png, or .dll, and should have at most three digits, no additional periods. Write a Python program to create a list of True/False that determine whether candidate filename is valid or not.

```Input:
['abc.txt', 'windows.dll', 'tiger.png', 'rose.jpg', 'test.py', 'win32.exe']

Output:
['Yes', 'Yes', 'Yes', 'Yes', 'No', 'Yes']

Input:
['.txt', 'windows.exe', 'tiger.jpeg', 'rose.c', 'test.java']

Output:
['No', 'Yes', 'No', 'No', 'No']
```

Pictorial Presentation:

Sample Solution-1:

Python Code:

``````def test(file_names):
return ["Yes" if
f.split(".")[1:] in [['txt'], ['png'], ['dll'], ['exe'], ['jpg']] and f[0].isalpha() and sum(c.isdigit() for c in f) < 4
else "No"
for f in file_names]

file_names = ['abc.txt', 'windows.dll', 'tiger.png', 'rose.jpg', 'test.py', 'win32.exe']
print("Original list of files:")
print(file_names)
print("Valid filenames:")
print(test(file_names))
file_names = ['.txt', 'windows.exe', 'tiger.jpeg', 'rose.c', 'test.java']
print("\nOriginal list of files:")
print(file_names)
print("Valid filenames:")
print(test(file_names))
``````

Sample Output:

```Original list of files:
['abc.txt', 'windows.dll', 'tiger.png', 'rose.jpg', 'test.py', 'win32.exe']
Valid filenames:
['Yes', 'Yes', 'Yes', 'Yes', 'No', 'Yes']

Original list of files:
['.txt', 'windows.exe', 'tiger.jpeg', 'rose.c', 'test.java']
Valid filenames:
['No', 'Yes', 'No', 'No', 'No']
```

Flowchart:

## 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:

Python Code:

``````#License: https://bit.ly/3oLErEI
def test(file_names):
valids = []
for sat in file_names:
n_digits = sum(c.isdigit() for c in sat)
if sat.split(".")[1:] not in [['txt'], ['dll'], ['exe']] or not sat[0].isalpha() or n_digits > 3:
valids.append("No")
else:
valids.append("Yes")
return valids

file_names = ['abc.txt', 'windows.dll', 'tiger.png', 'rose.jpg', 'test.py', 'win32.exe']
print("Original list of files:")
print(file_names)
print("Valid filenames:")
print(test(file_names))
file_names = ['.txt', 'windows.exe', 'tiger.jpeg', 'rose.c', 'test.java']
print("\nOriginal list of files:")
print(file_names)
print("Valid filenames:")
print(test(file_names))

``````

Sample Output:

```Original list of files:
['abc.txt', 'windows.dll', 'tiger.png', 'rose.jpg', 'test.py', 'win32.exe']
Valid filenames:
['Yes', 'Yes', 'No', 'No', 'No', 'Yes']

Original list of files:
['.txt', 'windows.exe', 'tiger.jpeg', 'rose.c', 'test.java']
Valid filenames:
['No', 'Yes', 'No', 'No', 'No']
```

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

Clamps num within the inclusive range specified by the boundary values x and y:

Example:

```def tips_clamp_num(num,x,y):
return max(min(num, max(x, y)), min(x, y))
print(tips_clamp_num(2, 4, 6))
print(tips_clamp_num(1, -1, -6))
```

Output:

```4
-1
```