Go for Python Programmers

Go for Python Programmers presented at DevConf.CZ 2019

Transcript

1. Go for Python Programmers Alexandre Vicenzi Pythonista at Red Hat
2. History • Robert Griesemer, Rob Pike and Ken Thompson • Google • Began in late 2007 • First public release in 2009 • First stable release in 2012
3. Why a new language? • Frustration with existing languages • Programming had become too difficult • Many years with a quiet landscape of choices • To take advantage of networking and multicore
4. Features • Compiles to native machine code • Memory safety • Garbage collection • Concurrency
5. Go vs Python
6. Code organization • Keep everything in a single workspace ◦ src - source files ◦ bin - executable commands • GOPATH environment variable ($HOME/go) • Workspace contains multiple repositories • Import path is the package location in the workspace
7. Package management • No official tool yet • Tools ◦ dep - The official experiment ◦ Godep ◦ Govendor ◦ Glide ◦ many others • Modules ◦ Preliminary support ◦ No need for GOPATH anymore ◦ Go 1.13 (August 2019)
8. Object Oriented Programming • No classes • No inheritance • No generics • Interfaces • Composition • Type embedding
9. Pointers • Everything in Go is passed by value • No pointer arithmetic • Pointer is represented by * • * is also used to “dereference” • & returns the memory address • new function
10. Go concurrency • Goroutines ◦ Function executing concurrently with other functions in the same address space ◦ Goroutines are multiplexed onto multiple OS threads • Channels ◦ Typed, synchronized, thread-safe by design ◦ Buffered and Unbuffered (default)
11. What else is different? • No decorators • No named or optional arguments • No iterators • No generators • No exceptions • Part of the C family • Labels and goto
12. Your first program package main import "fmt" func main() { fmt.Println("Hello, world.") }
13. factorial.py def factorial(n): if n == 0: return 1 return n * factorial(n - 1) print(factorial(5))
14. factorial.go package main import "fmt" func factorial(n int) int { if n == 0 { return 1 } return n * factorial(n-1) } func main() { fmt.Println(factorial(5)) }
15. fibonacci.py def fibonacci(n): a, b = 0, 1 yield a for i in range(n): a, b = b, a + b yield a for i in fibonacci(10): print(i)
16. fibonacci.go package main import "fmt" func fibonacci(c chan int, n int) { a, b := 0, 1 c <- a for i := 0; i < n; i++ { a, b = b, a+b c <- a } close(c) } func main() { c := make(chan int) go fibonacci(c, 10) for i := range c { fmt.Println(i) } }
18. Conclusion Go is • Simple • Concurrent • Robust • Fun
19. Next steps • golang.org • tour.golang.org • groups.google.com/d/forum/golang-nuts • golang-book.com
20. Thank you Alexandre Vicenzi Pythonista at Red Hat alexandrevicenzi.com @alxvicenzi