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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