Question

import numpy as np

import matplotlib.pyplot as plt

import pandas as pd

fig = plt.figure(figsize=(11.69,8.27), dpi=100)

bottom, top = 0.1, 0.9
left, right = 0.1, 0.8

fig.subplots_adjust(top=top, bottom=bottom, left=left, right=right, hspace=0.15, wspace=0.25)

for num in range(12):

    ax = fig.add_subplot(3,4,num+1)
    im = ax.scatter(np.random.rand(10), np.random.rand(10), 12, np.random.rand(10), cmap='magma')

fig.text(0.5, 0.02, 'x label', ha='center', fontsize=16)

fig.text(0.02, 0.5, 'ylabel ', va='center', rotation='vertical', fontsize=16)

cbar_ax = fig.add_axes([0.85, bottom, 0.05, top-bottom])
fig.colorbar(im, cax=cbar_ax)

fig.savefig("example.pdf", dpi=fig.dpi, pad_inches=0.3)

它给了我所有数据，但我只需要3个随机数据。我有Google会随机获得N个数据，但为什么不为我工作？

Answer 1

function get() {
    return new Promise(function (resolve, reject) {

        Card.aggregate([
            { $sample: {size: Number(req.body.wordCount)} }, 
            { $match:  {"deckId": new mongoose.Types.ObjectId(req.body.deckId)} }
        ]).exec(function(err,result){
            if(err){
                reject(err);
            }else{
                resolve(result)
            }
        });

    });
}

获取随机n记录不会崩溃

1 个答案: