10 Essential Python Code Snippets for Everyday Development

1️⃣ Check if a string is empty:

def is_empty(s):
    return not s.strip()

2️⃣ Convert a string to a date (default format "%Y-%m-%d"):

from datetime import datetime

def str_to_date(date_str, format="%Y-%m-%d"):
    return datetime.strptime(date_str, format)

3️⃣ Remove duplicates from a list while preserving order:

def unique_list(lst):
    seen = set()
    return [x for x in lst if not (x in seen or seen.add(x))]

4️⃣ Get all files in a directory (excluding sub‑directories):

import os

def list_files(dir_path):
    return [f for f in os.listdir(dir_path) if os.path.isfile(os.path.join(dir_path, f))]

5️⃣ Compute the average of a numeric list:

def average(numbers):
    return sum(numbers) / len(numbers)

6️⃣ Read the entire contents of a file:

def read_file(file_path):
    with open(file_path, 'r') as file:
        return file.read()

7️⃣ Convert a dictionary to a URL query string:

def dict_to_query_string(d):
    return '&'.join(f"{k}={v}" for k, v in d.items())

8️⃣ Check whether a number falls within a given inclusive range:

def is_in_range(number, start, end):
    return start <= number <= end

9️⃣ Find the index of the maximum value in a list:

def find_max_index(lst):
    return lst.index(max(lst))

🔟 Convert a list to a comma‑separated string:

def list_to_csv(lst):
    return ','.join(str(x) for x in lst)

These small but handy utilities form a core part of every Python developer's toolbox.