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']

Visual Presentation:

Python: A valid filename.

Sample Solution-1:

Python Code:

# Define a function named 'test' that takes a list of file names as input
def test(file_names):
    # Use a list comprehension to iterate over each file name in the input list
    return ["Yes" if
            # Check conditions for a valid file name:
            # - The file extension is one of ['txt', 'png', 'dll', 'exe', 'jpg']
            # - The first character of the file name is alphabetic
            # - The number of digits in the file name is less than 4
            f.split(".")[1:] in [['txt'], ['png'], ['dll'], ['exe'], ['jpg']] and f[0].isalpha() and sum(c.isdigit() for c in f) < 4
            # Return "Yes" if all conditions are met, otherwise "No"
            else "No"
            # Iterate over each file name 'f' in the input list
            for f in file_names]

# Set a list of file names
file_names = ['abc.txt', 'windows.dll', 'tiger.png', 'rose.jpg', 'test.py', 'win32.exe']
# Print a message indicating the original list of files
print("Original list of files:")
# Print the original list of file names
print(file_names)
# Print a message indicating valid filenames and use the 'test' function to determine validity
print("Valid filenames:")
# Print the result of the 'test' function applied to the file names
print(test(file_names))

# Set another list of file names
file_names = ['.txt', 'windows.exe', 'tiger.jpeg', 'rose.c', 'test.java']
# Print a message indicating the original list of files
print("\nOriginal list of files:")
# Print the original list of file names
print(file_names)
# Print a message indicating valid filenames and use the 'test' function to determine validity
print("Valid filenames:")
# Print the result of the 'test' function applied to the file names
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:

Flowchart: Python - A valid filename..

Sample Solution-2:

Python Code:

# Define a function named 'test' that takes a list of file names as input
def test(file_names):
    # Initialize an empty list to store the validity status of each file name
    valids = []
    
    # Iterate over each file name in the input list using a for loop
    for sat in file_names:
        # Count the number of digits in the current file name
        n_digits = sum(c.isdigit() for c in sat)
        
        # Check conditions for a valid file name:
        # - The file extension is one of ['txt', 'dll', 'exe']
        # - The first character of the file name is alphabetic
        # - The number of digits in the file name is less than or equal to 3
        if sat.split(".")[1:] not in [['txt'], ['dll'], ['exe']] or not sat[0].isalpha() or n_digits > 3:
            # Append "No" to the 'valids' list if the conditions are not met
            valids.append("No")
        else:
            # Append "Yes" to the 'valids' list if all conditions are met
            valids.append("Yes")
    
    # Return the list of validity statuses
    return valids

# Set a list of file names
file_names = ['abc.txt', 'windows.dll', 'tiger.png', 'rose.jpg', 'test.py', 'win32.exe']
# Print a message indicating the original list of files
print("Original list of files:")
# Print the original list of file names
print(file_names)
# Print a message indicating valid filenames and use the 'test' function to determine validity
print("Valid filenames:")
# Print the result of the 'test' function applied to the file names
print(test(file_names))

# Set another list of file names
file_names = ['.txt', 'windows.exe', 'tiger.jpeg', 'rose.c', 'test.java']
# Print a message indicating the original list of files
print("\nOriginal list of files:")
# Print the original list of file names
print(file_names)
# Print a message indicating valid filenames and use the 'test' function to determine validity
print("Valid filenames:")
# Print the result of the 'test' function applied to the file names
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:

Flowchart: Python - A valid filename.

Python Code Editor :

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous: Biggest even number between two numbers inclusive.
Next: Find numbers that are adjacent to a prime number in the list, sorted without duplicates.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



Become a Patron!

Follow us on Facebook and Twitter for latest update.

It will be nice if you may share this link in any developer community or anywhere else, from where other developers may find this content. Thanks.

https://198.211.115.131/python-exercises/puzzles/python-programming-puzzles-59.php