Writing a random number generator in python

The purpose of the program is to save typing. It is not a goal to handle all features of the 'argparse' module, but rather to produce code that runs, and, if desired, can be easily modified to take advantage of more advanced argparse features; and of course to modify the program to do whatever the programs is intended to do. It is easier to modify the generated code to add these advanced argparse features. If the user copies the Python 2.

Writing a random number generator in python

I don't request random values which I don't end up using. Throwing away values from the random number generator does not make those numbers that you use more secure. I don't use single-letter variable names or abbreviations like con or mut that obscure the meaning.

This solution features far less duplicate code. Did you calculate r.

Numerical Programming

Now the code is cleaned up so that we can do some more substantial reviewing. There is no use in separating between numbers, lowercase letters, and uppercase letters. They all should be in the same character pool so that each character has the same probability of occuring at each position in the password.

With your current methods, a digit is much more likely to occur than any given letter, simply because there are less digits than letters. Consider packing all of this functionality into a single, convenient function instead: A seed is the initial state of a random number generator.

writing a random number generator in python

When set to the same seed each time, the random number generator will produce the same sequence of numbers. Use clear, obvious names for your variables rather than using technical lingo if you aren't sure what it means — although a quick trip to Wikipedia would have cleared that up.

You issue a few Windows-only system commands such as cls. Unless this is central to the working of your application, don't manipulate the console, such as setting the color or clearing the screen. Users can do this themselves if they want to.

Generators - Python Wiki

Removing these commands also makes your code usable on other operating systems like OS X or Linux. You are using the random library as a random number generator.

The numbers produced by this library aren't really random, they are just pseudo-random. This is usually not an issue as long as a really random seed is chosen, but because the number sequence is derived algorithmically, it should not be used for really really important stuff. Most passwords are only important and not really really important, so this should be fine ;- but it's good to remember that real randomness is something different.

That is one aspect where the security of your program is not optimal, but good enough. Writing the password to a file is however absolutely irresponsible.

When the password is only displayed on the command line, we can assume that it will only be immediately visible until the screen is cleared or other content has caused it to scroll out of sight.

It will be held in memory for a while longer, but at least a rebooting of the system will remove any trace of this.

A plain text file however is much more persistent it stays there after a reboot. It is also much easier for other users to access that password. Don't store secrets at all, or if you have to store them, secure them properly. You should consider writing your Python code so that it is usable both as a module, and a script.

Now we can both do:Python uses the Mersenne Twister as the core generator. It produces bit precision floats and has a period of 2** The underlying implementation in C is both fast and threadsafe. The Mersenne Twister is one of the most extensively tested random number generators in existence.


For example, a sequence of length is the largest. Writing Python Command-Line Tools With Click; Browse All Tutorials» Working with Random Numbers in Python.

By Dan Bader — Get free updates of new posts here. use timberdesignmag.comRandom which uses a cryptographically secure pseudo-random number generator. Python Program to Generate a Random Number. In this example, you will learn to generate a random number in Python.

To understand this example, you should have the knowledge of following Python programming topics: Python Input, Output and Import; Python Random Module;.

writing a random number generator in python

The simplification of code is a result of generator function and generator expression support provided by Python. To illustrate this, we will compare different implementations that implement a function, "firstn", that represents the first n non-negative integers, where n is a really big number, and assume (for the sake of the examples in this.

One last detail: Don't forget to call timberdesignmag.com() with a seed value in order to initialize the random number generator. If you use the same seed value all the time, the random number generator will create the same sequence of random integers.

generator expression. A number of tools in Python accept key functions to control how elements are ordered or grouped. For instance, writing timberdesignmag.com() or timberdesignmag.com() makes it clear that those functions are implemented by the random and itertools modules.

Ranged random-number generation is slow in Python… – Daniel Lemire's blog