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PyCon 2011 Atlanta

March 9th–17th

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(Re-)Introduction to C for Pythonistas

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Experienced / Tutorial
Noah Kantrowitz
March 10th 9 a.m. – 12:20 p.m.
While Python is great for many things, C is still the lingua franca of the programming world. Whether you need to rewrite that critical loop or you want to get involved in CPython development, knowing the basics of C is an important skill for even the most hardened of Python coders. Over the course of this tutorial we will go over the basics of C and where Python programmers may get tripped up.

Abstract

  • Introduction (10 minutes)
  • Environment setup (10 minutes)
    • gcc basics
    • Check for make
  • Types (10 minutes)
    • int, char, float
    • unsigned keyword
    • pointers
      • void*
    • arrays
    • strings
      • char*
      • char[]
    • structs
      • unions
    • enums
  • Writing a function (10 minutes)
    • Function signatures
      • void
    • Semicolon, semicolon, semicolon
    • Declare variables at the top
    • return()
    • ints all the way down
    • int main(int argc, char **argv)
  • Exercise 1 (10 minutes)
    • Quick overview of printf
    • gcc -o
    • Start with hello world
    • Extend to ./ex1 name --> "Hello name"
  • Blocks (10 minutes)
    • if, while (same as Python, just mention for syntax)
    • for
    • do/while
    • "simple" blocks
  • Exercise 2 (10 minutes)
    • ./ex2 hello --> "Hello world"
    • ./ex2 list a b c --> "a\nb\nc\n"
    • Use both if and for
      • Confirm understanding of C-style for loops
  • Preprocessor (5 minutes)
    • #include
      • "" vs. <>
      • <stdio> vs. <stdio.h>
    • #define
      • #ifdef, #if
    • #pragma once
  • Headers (5 minute)
    • How to declare a function
    • Forward definitions
      • Enums
  • Exercise 3 (10 minutes)
    • Must use multiple files
    • ./ex3 10 --> "2 3 5 7"
    • ./ex3 5 13 --> "5 7 11"
  • Break (15 minutes)
  • The compiler process (10 minutes)
    • Preprocess
      • gcc -D
      • gcc -I
    • Compile
      • Assemble
      • gcc -c
    • Link
      • gcc -l
      • gcc -L
  • make basics (15 minutes)
    • Basic targets
    • Dependencies
    • Macros
    • Suffix targets
  • Exercise 4 (10 minutes)
    • Create a makefile for ex3
  • Useful functions (20 minutes)
    • printf()
      • %s, %i, %d, %f
    • string.h
      • strlen()
      • strcpy() vs. strncpy()
      • strncmp()
    • malloc()/free()
      • sizeof()
      • calloc()
      • realloc()
    • memcpy(), memmove()
    • stdio.h
      • fopen()
      • FILE*
      • fread()
      • fwrite()
      • fgets()
      • fclose()
      • snprintf()
      • fprintf()
    • stdint.h
      • int32_t
      • uint64_t
    • math.h
      • import math
      • M_PI, M_E
    • stdlib.h
      • atoi(), atof(), strtol()
      • random()
      • exit()
      • system()
      • qsort()
        • Comparator functions
      • abs() (not in math.h)
      • NULL
      • size_t
  • Runtimes (5 minutes)
    • GLib
    • Python
      • C extensions, give some links
    • C++
      • STL
      • Boost
      • QtCore
      • wxBase