# -*- coding: utf-8 -*- """Module to generate ascii charts. This module provides a single function `plot` that can be used to generate an ascii chart from a series of numbers. The chart can be configured via several options to tune the output. """ from __future__ import division from math import ceil, floor, isnan black = "\033[30m" red = "\033[31m" green = "\033[32m" yellow = "\033[33m" blue = "\033[34m" magenta = "\033[35m" cyan = "\033[36m" lightgray = "\033[37m" default = "\033[39m" darkgray = "\033[90m" lightred = "\033[91m" lightgreen = "\033[92m" lightyellow = "\033[93m" lightblue = "\033[94m" lightmagenta = "\033[95m" lightcyan = "\033[96m" white = "\033[97m" reset = "\033[0m" __all__ = [ 'plot', 'black', 'red', 'green', 'yellow', 'blue', 'magenta', 'cyan', 'lightgray', 'default', 'darkgray', 'lightred', 'lightgreen', 'lightyellow', 'lightblue', 'lightmagenta', 'lightcyan', 'white', 'reset', ] # Python 3.2 has math.isfinite, which could have been used, but to support older # versions, this little helper is shorter than having to keep doing not isnan(), # plus the double-negative of "not is not a number" is confusing, so this should # help with readability. def _isnum(n): return not isnan(n) def colored(char, color): if not color: return char else: return color + char + reset def plot(series, cfg=None): """Generate an ascii chart for a series of numbers. `series` should be a list of ints or floats. Missing data values in the series can be specified as a NaN. In Python versions less than 3.5, use float("nan") to specify an NaN. With 3.5 onwards, use math.nan to specify a NaN. >>> series = [1,2,3,4,float("nan"),4,3,2,1] >>> print(plot(series)) 4.00 ┤ ╭╴╶╮ 3.00 ┤ ╭╯ ╰╮ 2.00 ┤╭╯ ╰╮ 1.00 ┼╯ ╰ `series` can also be a list of lists to support multiple data series. >>> series = [[10,20,30,40,30,20,10], [40,30,20,10,20,30,40]] >>> print(plot(series, {'height': 3})) 40.00 ┤╮ ╭╮ ╭ 30.00 ┤╰╮╯╰╭╯ 20.00 ┤╭╰╮╭╯╮ 10.00 ┼╯ ╰╯ ╰ `cfg` is an optional dictionary of various parameters to tune the appearance of the chart. `min` and `max` will clamp the y-axis and all values: >>> series = [1,2,3,4,float("nan"),4,3,2,1] >>> print(plot(series, {'min': 0})) 4.00 ┼ ╭╴╶╮ 3.00 ┤ ╭╯ ╰╮ 2.00 ┤╭╯ ╰╮ 1.00 ┼╯ ╰ 0.00 ┤ >>> print(plot(series, {'min': 2})) 4.00 ┤ ╭╴╶╮ 3.00 ┤ ╭╯ ╰╮ 2.00 ┼─╯ ╰─ >>> print(plot(series, {'min': 2, 'max': 3})) 3.00 ┤ ╭─╴╶─╮ 2.00 ┼─╯ ╰─ `height` specifies the number of rows the graph should occupy. It can be used to scale down a graph with large data values: >>> series = [10,20,30,40,50,40,30,20,10] >>> print(plot(series, {'height': 4})) 50.00 ┤ ╭╮ 40.00 ┤ ╭╯╰╮ 30.00 ┤ ╭╯ ╰╮ 20.00 ┤╭╯ ╰╮ 10.00 ┼╯ ╰ `format` specifies a Python format string used to format the labels on the y-axis. The default value is "{:8.2f} ". This can be used to remove the decimal point: >>> series = [10,20,30,40,50,40,30,20,10] >>> print(plot(series, {'height': 4, 'format':'{:8.0f}'})) 50 ┤ ╭╮ 40 ┤ ╭╯╰╮ 30 ┤ ╭╯ ╰╮ 20 ┤╭╯ ╰╮ 10 ┼╯ ╰ """ if len(series) == 0: return '' if not isinstance(series[0], list): if all(isnan(n) for n in series): return '' else: series = [series] cfg = cfg or {} colors = cfg.get('colors', [None]) minimum = cfg.get('min', min(filter(_isnum, [j for i in series for j in i]))) maximum = cfg.get('max', max(filter(_isnum, [j for i in series for j in i]))) default_symbols = ['┼', '┤', '╶', '╴', '─', '╰', '╭', '╮', '╯', '│'] symbols = cfg.get('symbols', default_symbols) if minimum > maximum: raise ValueError('The min value cannot exceed the max value.') interval = maximum - minimum offset = cfg.get('offset', 3) height = cfg.get('height', interval) ratio = height / interval if interval > 0 else 1 min2 = int(floor(minimum * ratio)) max2 = int(ceil(maximum * ratio)) def clamp(n): return min(max(n, minimum), maximum) def scaled(y): return int(round(clamp(y) * ratio) - min2) rows = max2 - min2 width = 0 for i in range(0, len(series)): width = max(width, len(series[i])) width += offset placeholder = cfg.get('format', '{:8.2f} ') result = [[' '] * width for i in range(rows + 1)] # axis and labels for y in range(min2, max2 + 1): label = placeholder.format(maximum - ((y - min2) * interval / (rows if rows else 1))) result[y - min2][max(offset - len(label), 0)] = label result[y - min2][offset - 1] = symbols[0] if y == 0 else symbols[1] # zero tick mark # first value is a tick mark across the y-axis d0 = series[0][0] if _isnum(d0): result[rows - scaled(d0)][offset - 1] = symbols[0] for i in range(0, len(series)): color = colors[i % len(colors)] # plot the line for x in range(0, len(series[i]) - 1): d0 = series[i][x + 0] d1 = series[i][x + 1] if isnan(d0) and isnan(d1): continue if isnan(d0) and _isnum(d1): result[rows - scaled(d1)][x + offset] = colored(symbols[2], color) continue if _isnum(d0) and isnan(d1): result[rows - scaled(d0)][x + offset] = colored(symbols[3], color) continue y0 = scaled(d0) y1 = scaled(d1) if y0 == y1: result[rows - y0][x + offset] = colored(symbols[4], color) continue result[rows - y1][x + offset] = colored(symbols[5], color) if y0 > y1 else colored(symbols[6], color) result[rows - y0][x + offset] = colored(symbols[7], color) if y0 > y1 else colored(symbols[8], color) start = min(y0, y1) + 1 end = max(y0, y1) for y in range(start, end): result[rows - y][x + offset] = colored(symbols[9], color) return '\n'.join([''.join(row).rstrip() for row in result])