Python has three similar data structures that can hold an unordered collection of elements: list, tuple and set. Here's how they differ: initialization list: using the built-in list() or the square brackets ([]): list1 = list() # creates an empty list list2 = [] # also creates an empty list list3 = ['a', 'b', 'c', … Continue reading Difference among list, tuple and set in Python and when to use each one
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Debugging Python applications (plus free cheat sheet)
My primary debugging tool is to add print statements to my programs</confession_time>. Print statements are very easy to use and they work well for any simple scripts. But that's the catch: if you're debugging an application and/or a test file, print statements won't be enough or will just not work (in the case if tests … Continue reading Debugging Python applications (plus free cheat sheet)
Add a filename in the command line when running a Python script
OR: Run a Python script with arguments You can add arguments to the command line when running python scripts by importing the sys module from Python's standard library and using its argv function. Some examples: A simple script that displays the user name: def main(): name = 'Frodo' print(f'Hello, {name}') if __name__ == "__main__": main() … Continue reading Add a filename in the command line when running a Python script
Display nested dictionary content sorted by key in Python
Given a nested dictionary like this: dog_breeds = { 'Labrador Retriever': {'life_span': 14, 'male_weight': '36 Kg', 'female_weight': '32 Kg'}, 'Beagle': {'life_span': 15, 'male_weight': '11 Kg', 'female_weight': '10 Kg'}, 'German Shepherd': {'life_span': 13, 'male_weight': '40 Kg', 'female_weight': '32 Kg'}, 'Jack Russell Terrier': {'life_span': 16, 'male_weight': '8 Kg', 'female_weight': '8 Kg'}, 'Rottweiler': {'life_span': 10, 'male_weight': '60 Kg', … Continue reading Display nested dictionary content sorted by key in Python
Profiling: check how long it takes to run a Python script
From Python's official documentation: "A profile is a set of statistics that describes how often and for how long various parts of the program executed." Python's standard library provides two implementations of the same profiling interface: cProfile and profile but I always go with cProfile for short scripts because you can invoke it at run time like … Continue reading Profiling: check how long it takes to run a Python script
Map a string in Python with enumerate
Problem: create a map of the letters and indices in a string. My first approach was to loop over the string using range(len(s)), and checking if the letter exists in the map before adding it: s = 'mozzarella' mapped_s = {} for i in range(len(s)): if s[i] in mapped_s: mapped_s[s[i]].append(i) else: mapped_s[s[i]] = [i] print(f' mapped: … Continue reading Map a string in Python with enumerate
