dimitrilw

import os, os.path, sys, urllib2, requests

class PyPiError(Exception):
    def __init__(self, value):
        self.value = value
    def __str__(self):
        return repr(self.value)

def _chunk_report(bytes_so_far, chunk_size, total_size):
    if (total_size != None):

dimitrilw

import (
    // most already have these imported; putting here just in case
    "log" 
    "os"
)

var (
    // logger = log.New(os.Stdout, "", log.Lshortfile)
    logger1 = log.New(os.Stdout, "optional prefix: ", log.LstdFlags|log.Lshortfile)
    logger2 = log.New(os.Stdout, "log 2: ", log.Lshortfile)

dimitrilw

// remember that "slice magic" means that the underlying array of data 
// beyond the 'i'th value may still be available, so the slice should not
// be exported outside of the package, like to third-party software

func demoFilter(s []int) []int {
    i := 0
    for _, v := range s {
        if v > 1 { // some criteria; this is the filter
            s[i] = v
            i++

dimitrilw

// use "iota" for enumerated constants, like this:

const (
    a = iota // 0
    b        // 1
    c        // 2
    //...
    n        // n
)

dimitrilw

// for use with signed numbers, like an int, *not* a uint

func lsb(n int) int { return n & (-n) }

func demo() {
	for i := 0; i < 10; i++ {
		fmt.Printf("i %d as bits %04b lsb %b\n", i, i, lsb(i))
	}
}

dimitrilw

package main

import (
	"fmt"
	"sort"
)

// Slices implements the Go standard lib's Sort interface
// by having Len, Less, and Swap methods.
// This particular demo implementation sorts multiple slices,

dimitrilw

brew tap homebrew/cask-fonts
brew install --cask font-cascadia-code
brew install --cask font-cascadia-code-pl
brew install --cask font-cascadia-mono
brew install --cask font-cascadia-mono-pl

dimitrilw

// greatest common denominator
func gcd(a, b int) int {
    if b > a { a, b = b, a }
    if b == 0 { return a }
    return gcd(b, a%b)
}

dimitrilw

// returns unsorted slice of *all* factors, not just primes
func getFactors(n int) []int {
    res := []int{}
    for i := 1; i <= int(math.Sqrt(float64(n))); i++ {
        if n%i == 0 {
            res = append(res, i)
            if i*i != n {
                res = append(res, n/i)
            }
        }

dimitrilw

// https://en.wikipedia.org/wiki/Fenwick_tree
// https://www.youtube.com/watch?v=uSFzHCZ4E-8

type FenwickTree []int

// returns sum of all elements up to index 'i'
func (ft FenwickTree) sum(i int) int {
    res := 0
    for ; i > 0; i -= lsb(i) {
        res += ft[i]