在jupyter笔记本中使用Seaborn时出错（pyspark）

Question

我正在尝试使用Seaborn可视化数据。我在pyspark中使用SQLContext创建了一个数据帧。但是，当我调用lmplot时会导致错误。我不确定我错过了什么。下面是我的代码（我正在使用jupyter笔记本）：

import pandas as pd

from matplotlib import pyplot as plt

import seaborn as sns

from pyspark.sql import SQLContext

sqlContext = SQLContext(sc)

df = sqlContext.read.load('file:///home/cloudera/Downloads/WA_Sales_Products_2012-14.csv', 
                      format='com.databricks.spark.csv', 
                      header='true',inferSchema='true')

sns.lmplot(x='Quantity', y='Year', data=df)

Error trace:
---------------------------------------------------------------------------
 TypeError                                 Traceback (most recent call last)
<ipython-input-86-2a2b43993475> in <module>()
----> 2 sns.lmplot(x='Quantity', y='Year', data=df)

/home/cloudera/anaconda3/lib/python3.5/site-packages/seaborn/regression.py in lmplot(x, y, data, hue, col, row, palette, col_wrap, size, aspect, markers, sharex, sharey, hue_order, col_order, row_order, legend, legend_out, x_estimator, x_bins, x_ci, scatter, fit_reg, ci, n_boot, units, order, logistic, lowess, robust, logx, x_partial, y_partial, truncate, x_jitter, y_jitter, scatter_kws, line_kws)
    557                        hue_order=hue_order, size=size, aspect=aspect,
    558                        col_wrap=col_wrap, sharex=sharex, sharey=sharey,
--> 559                        legend_out=legend_out)
    560 
    561     # Add the markers here as FacetGrid has figured out how many levels of the

/home/cloudera/anaconda3/lib/python3.5/site-packages/seaborn/axisgrid.py in __init__(self, data, row, col, hue, col_wrap, sharex, sharey, size, aspect, palette, row_order, col_order, hue_order, hue_kws, dropna, legend_out, despine, margin_titles, xlim, ylim, subplot_kws, gridspec_kws)
    255         # Make a boolean mask that is True anywhere there is an NA
    256         # value in one of the faceting variables, but only if dropna is True
--> 257         none_na = np.zeros(len(data), np.bool)
    258         if dropna:
    259             row_na = none_na if row is None else data[row].isnull()

TypeError: object of type 'DataFrame' has no len()

任何帮助或指针都表示赞赏。先感谢您：-）

Answer 1

sqlContext.read.load(...)返回Spark-DataFrame。我不确定，seaborn是否可以自动将Spark-DataFrame转换为Pandas-Dataframe。

尝试：

sns.lmplot(x='Quantity', y='Year', data=df.toPandas())

df.toPandas()从Spark-DF返回pandas-DF。