Problem Formulation: How to Test if String Starts With Any Prefix From an Iterable? Given a string and multiple string prefixes in an iterable such as a list or a tuple. How to test whether the string starts with any of the provided prefixes? Here are three examples: s = ‘hello world’ prefixes = [‘hi’, … Read more
Python has four ways to calculate the n-th power (exponent) of x so that xⁿ=x*x*…*x that multiplies the base x with itself, and repeating this n-times. Method 1: Use the double-asterisk operator such as in x**n. Method 2: Use the built-in pow() function such as in pow(x, n). Method 3: Import the math library and … Read more
Have you ever wondered what happens in the system when you type https://app.finxter.com/ or https://google.com and press enter in your web browser? This is exactly what we will be covering in Python Networking. How the data flows from HTTP protocol to TCP/IP protocol stack. Then finally over the internet to fetch the data you requested. We discuss … Read more
Python Multiplication Table For Loop To calculate the multiplication table for a given number, iterate over all values i=0, 1, …, limit in a for loop and use the following statement as a loop body: print(number, ‘x’, i, ‘=’, number * i). This prints all equations, line by line, in the form i x j … Read more
When I started to learn Python 3, I used to be confused about the semantics of dividing two integers. Is the result a float or an integer value? The reason for my confusion was a nasty Java bug that I once found in my code. The code was supposed to perform a simple division of … Read more
[toc] Introduction Problem Formulation: Given a floating-point value. How to limit it to two decimal places in Python? Example: Let’s have a look at a program where you have to calculate the value of pi. Output: Perfect! pi yields you a value = 3.141592653589793. But, what if you need the value of pi only up … Read more
The double-frontslash // operator performs integer division and the single-frontslash / operator performs float division. An example for integer division is 40//11 = 3. An example for float division is 40/11 = 3.6363636363636362. A crucial lesson you need to master as a programmer is “division in Python”. What does it mean to divide in Python? … Read more
What regular expressions can be used to match Bitcoin addresses? A regular expression for validating Bitcoin addresses must check that the string is 26-35 characters long, start with “1” or “3” or “bc1” consists of uppercase or lowercase alphabetic and numeric characters, and ensure it doesn’t contain ambiguous characters. Not allowed are the uppercase letter … Read more
Python’s multiplication operator * multiplies two objects. The semantics of the multiplication depends on the operands’ data types. For example, multiplying two integers performs arithmetic multiplication whereas multiplying a list with an integer performs list concatenation. The specific return value of the multiplication operator is defined in a data types’ __mul__() magic method. Have a … Read more
In this article, I’ll develop a simple model of how to value Bitcoin. Valuation Thesis Bitcoin will replace the SWIFT bank-to-bank settlement protocol. Valuation Methodology Bitcoin is now the largest, most decentralized, and most secure international monetary network in the world. This makes it a perfect candidate for bank-to-bank settlements of high-value transactions (whitepaper). Currently, … Read more
In a previous article, we introduced the topic of object-oriented programming, or OOP for short. Then, we discussed classes and the topic of inheritance. This article will do a quick recap of inheritance, what it is, and why you’d use it. Then we’ll introduce the different types of inheritance you might encounter in your programming … Read more
[toc] ?️ Company Tags: Google Problem Formulation Given an array nums of n integers. Return an array containing all the integers in the range[1, n]that do not appear in nums. ✒️ Here, nums[i] is in the range [1, n]. ⚠️Constraints: n == nums.length 1 <= n <= 105 1 <= nums[i] <= n ?Examples Let’s have a look at some … Read more