Data Science

SQLite Python Placeholder – Four Methods for SQL Statements

Computer Science, Data Science, Python / By

Are you confusing about SQLite Python Placeholders? It’s time for better understanding! Learn how in this tutorial. Introduction SQLite is an embedded open-source relational database engine. Its developers, from SQLite.org, call it a self-contained, serverless, zero-configuration, fast, reliable and transactional SQL database engine.  It keeps things simple. SQLite “just works.” The SQLite library is also …

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List Difference | The Most Pythonic Way

Algorithms, Computer Science, Data Science, Python, Python List, Python One-Liners, Python Set / By

Short answer: The most Pythonic way to compute the difference between two lists l1 and l2 is the list comprehension statement [x for x in l1 if x not in set(l2)]. This works even if you have duplicate list entries, it maintains the original list ordering, and it’s efficient due to the constant runtime complexity …

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Python Freelancing | How to Exploit This Disruptive Mega Trend (as a Coder)

Coding Business, Computer Science, Data Science, Machine Learning, Productivity, Python / By

Short summary of the main points in the video: Freelancing is a mega-trend that will disrupt the organization of the world’s labor in the next 10-20 years. Freelancing platforms such as Upwork and Fiverr grow at 20% per year. You can participate in this trend by focusing on one tiny niche—and become world-class at it. …

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The Most Pythonic Way to Convert a List to a String

Computer Science, Data Science, Python, Python List, Python One-Liners, Python String / By

To convert a list lst of strings to a string, use the ”.join(lst) method with an empty separator string between the elements. If you have a list of objects, first convert each element to a string and join the result with the generator expression ”.join(str(x) for x in lst). Problem: Given a list of elements. …

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Python Join List of DataFrames

Data Science, Data Structures, Pandas Library, Python, Python List / By

To join a list of DataFrames, say dfs, use the pandas.concat(dfs) function that merges an arbitrary number of DataFrames to a single one. When browsing StackOverflow, I recently stumbled upon the following interesting problem. By thinking about solutions to those small data science problems, you can improve your data science skills, so let’s dive into …

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How to Convert a List to a NumPy Array?

Computer Science, Data Science, Data Structures, Python, Python List, The Numpy Library / By

To convert a Python list to a NumPy array, use either of the following two methods: The np.array() function that takes an iterable and returns a NumPy array creating a new data structure in memory. The np.asarray() function that takes an iterable as argument and converts it to the array. The difference to np.array() is …

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[Collection] 10 Best NumPy Cheat Sheets Every Python Coder Must Own

Leave a Comment / Cheat Sheets, Computer Science, Data Science, Machine Learning, Productivity, Python, The Numpy Library / By

Little time to learn NumPy? This article shows you the ten most amazing NumPy cheat sheets. Download them, print them, and pin them to your wall — and watch your data science skills grow! 🐱‍🏍 All NumPy cheat sheets in this article are 100% free. All links open in a new tab (so feel free …

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The Ultimate Guide to NumPy Cumsum in Python

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Definition np.cumsum(x): The function computes the cumulative sum of a NumPy array. For an array x with elements [a b c d] the cumulative sum is [a a+b a+b+c a+b+c+d]. Formally, each array element with index i is the sum of all elements with index j<i. numpy.cumsum(a, axis=None, dtype=None, out=None) Arguments: a — Array-like data …

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[NumPy vs Python] What are Advantages of NumPy Arrays over Regular Python Lists?

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The Python built-in list data type is powerful. However, the NumPy array has many advantages over Python lists. What are they? Advantages NumPy Advantages Python Lists Multi-dimensional Slicing Library-Independent Broadcasting Functionality Intuitive Processing Speed Less Complicated Memory Footprint Heterogeneous List Data Allowed Many Convenience Methods Arbitrary Data Shape (Non-Square Matrix) Let’s dive into the most …

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