如何在matplotlib中进行多列文本注释？

Question

matplotlib 的legend()方法有一个ncol参数可以将内容布置在多列中。

我想在文本注释中做同样的事情。

我可以将多行文本字符串（即包含\ns 的文本字符串）传递给annotate()，但如何将内容排列为两列？

• 使用制表符？他们似乎什么也没做

• 使用两个单独的文本注释？但我想要在两列周围有一个圆形边框（bbox）

• 使用类似 ncol 的东西？它可以根据我要求的列数换行

Answer 1

我找不到一个好的方法来做到这一点，所以我编写了一个函数来完成工作。尝试一下，看看它是否满足您的需要。def place_column_text(ax, text, xy, wrap_n, shift, bbox=False, **kwargs):    """ Creates a text annotation with the text in columns.    The text columns are provided by a list of strings.    A surrounding box can be added via bbox=True parameter.    If so, FancyBboxPatch kwargs can be specified.        The width of the column can be specified by wrap_n,    the shift parameter determines how far apart the columns are.    The axes are specified by the ax parameter.    Requires:    import textwrap    import matplotlib.patches as mpatches    """    # place the individual text boxes, with a bbox to extract details from later    x,y = xy    n = 0    text_boxes = []    for i in text:        text = textwrap.fill(i, wrap_n)        box = ax.text(x = x + n, y = y, s=text, va='top', ha='left',                         bbox=dict(alpha=0, boxstyle='square,pad=0'))        text_boxes.append(box)        n += shift        if bbox == True: # draw surrounding box        # extract box data        plt.draw() # so we can extract real bbox data        # first let's calulate the height of the largest bbox        heights=[]        for box in text_boxes:            heights.append(box.get_bbox_patch().get_extents().transformed(ax.transData.inverted()).bounds[3])        max_height=max(heights)        # then calculate the furthest x value of the last bbox        end_x = text_boxes[-1].get_window_extent().transformed(ax.transData.inverted()).xmax        # draw final        width = end_x - x        fancypatch_y = y - max_height        rect = mpatches.FancyBboxPatch(xy=(x,fancypatch_y), width=width, height=max_height, **kwargs)        ax.add_patch(rect)这是它的使用情况：import matplotlib.patches as mpatchesimport textwrapfig, ax = plt.subplots(2,2,sharex=True, sharey=True,figsize=(16,12))fig.subplots_adjust(hspace=0.05, wspace=0.05)ax1, ax2, ax3, ax4 = ax.flatten()for a in ax.flatten():    a.plot(range(0,20),range(0,20), alpha=0)# the text to be split into columns and annotatedcol_text = ['Colum 1 text is this sentence here.',            'The text for column two is going to be longer',            'Column 3 is the third column.',            'And last but not least we have column 4. In fact this text is the longest.']# use the function to place the textplace_column_text(ax=ax1,text=col_text, xy=(1,10), wrap_n=10, shift=4.2)place_column_text(ax=ax2,text=col_text, xy=(0,19), wrap_n=17, bbox=True, shift=5, ec='red', fc='w', boxstyle='square')place_column_text(ax=ax3,text=col_text, xy=(2,18), wrap_n=6, bbox=True, shift=2.7, ec='blue', fc = 'blue' , alpha=0.3, boxstyle='round,pad=1')place_column_text(ax=ax4,text=col_text, xy=(3,12), wrap_n=10, bbox=True, shift=3, ec='red', fc='w', boxstyle='circle, pad=3')plt.show()结果：