ResistorsColor.py

from labelannotator import *
import re

resistor_colors = {
  -1: '#CFB53B',  # gold
  -2: '#C0C0C0',  # silver
  0: '#000000',   # black
  1: '#964B00',   # brown
  2: '#FF0000',   # red
  3: '#FFA500',   # orange
  4: '#FFFF00',   # yellow
  5: '#9ACD32',   # green
  6: '#6495ED',   # blue
  7: '#EE82EE',   # violet
  8: '#A0A0A0',   # grey
  9: '#FFFFFF',   # white
}

# maps from percent tolerance to colors
resistor_tolerance_colors = {
  1: '#964B00',   # brown
  2: '#FF0000',   # red
  0.5: '#9ACD32',   # green
  0.25: '#6495ED',   # blue
  0.1: '#EE82EE',   # violet
  0.05: '#A0A0A0',   # grey
  5: '#CFB53B',   # gold
  10: '#C0C0C0',   # silver
}

resistance_multiplier = {
  'k': 3,
  'M': 6,
  'G': 9,
}

def colors_dict(res_str):
  # Do calculations with string manipulation to avoid floating-point loss of
  # precision and things like 4.6999999999k.

  if not res_str:
    return {
      'res_color1': '#FFFFFF',
      'res_color2': '#FFFFFF',
      'res_color3': '#FFFFFF',
      'res_stroke': '#FFFFFF',
    }  
  
  if res_str[-2].isalpha():
    mult_str = res_str[-2]
    res_nopow_str = res_str[:-2]
    assert mult_str in resistance_multiplier, "Unknown multiplier '%s'" % mult_str
    mult_pow = resistance_multiplier[mult_str]
  else:
    mult_pow = 0
    res_nopow_str = res_str[:-1]

  dot_point = res_nopow_str.find('.')
  if dot_point > 0:
    assert not (dot_point == 1 and res_nopow_str[0] == '0'), "TODO: handle <1ohm codes"
    mult_code = dot_point - 2 + mult_pow
    nodot_str = res_nopow_str[0:dot_point] + res_nopow_str[dot_point+1:]
  else:
    mult_code = len(res_nopow_str) - 2 + mult_pow

    nodot_str = res_nopow_str

  val1_code = int(nodot_str[0])
  if len(nodot_str) > 1:
    val2_code = int(nodot_str[1])
    assert nodot_str[2:] == '0'*(len(nodot_str) - 2)
  else:
    val2_code = 0
    
  return {
    'res_color1': resistor_colors[val1_code],
    'res_color2': resistor_colors[val2_code],
    'res_color3': resistor_colors[mult_code],
    'res_stroke': '#000000',
  }  

def AddColor(row_dict):
  retval = {}
  for i in range(1,4):
    res_str = row_dict['val_' + str(i)]
    retval.update( {k + '_' + str(i): v for (k, v) in colors_dict(res_str).items()} )
  return retval

load() \
    .map_append(PriorityMap(['type'], 'title')) \
    .map_append(PriorityMap(['desc'], 'quickdesc')) \
    .map_append(StaticField('pcost', '')) \
    .map_append(StaticField('bg_color', '#FFFFFF')) \
    .map_append(AddColor) \
    .write()