PySpark-显示数据框中的列数据类型计数

Question

如何像使用熊猫数据框那样查看Spark数据框中每种数据类型的计数？例如，假设df是熊猫数据帧：>>> df.info(verbose=True)<class 'pandas.core.frame.DataFrame'>RangeIndex: 5 entries, 0 to 4Data columns (total 3 columns):int_col      5 non-null int64text_col     5 non-null objectfloat_col    5 non-null float64**dtypes: float64(1), int64(1), object(1)**memory usage: 200.0+ bytes我们可以很清楚地看到每种数据类型的计数。如何使用Spark数据框执行类似操作？也就是说，如何看到有多少列是浮动的，有多少列是int的，有多少列是对象的？

Answer 1

下面的代码应该可以为您带来理想的结果

# create data frame 

df = sqlContext.createDataFrame(

[(1,'Y','Y',0,0,0,2,'Y','N','Y','Y'),

 (2,'N','Y',2,1,2,3,'N','Y','Y','N'),

 (3,'Y','N',3,1,0,0,'N','N','N','N'),

 (4,'N','Y',5,0,1,0,'N','N','N','Y'),

 (5,'Y','N',2,2,0,1,'Y','N','N','Y'),

 (6,'Y','Y',0,0,3,6,'Y','N','Y','N'),

 (7,'N','N',1,1,3,4,'N','Y','N','Y'),

 (8,'Y','Y',1,1,2,0,'Y','Y','N','N')

],

('id', 'compatible', 'product', 'ios', 'pc', 'other', 'devices', 'customer', 'subscriber', 'circle', 'smb')

)

# Find data types of data frame

datatypes_List = df.dtypes

# Querying datatypes_List gives you column and its data type as a tuple

datatypes_List

[('id', 'bigint'), ('compatible', 'string'), ('product', 'string'), ('ios', 'bigint'), ('pc', 'bigint'), ('other', 'bigint'), ('devices', 'bigint'), ('customer', 'string'), ('subscriber', 'string'), ('circle', 'string'), ('smb', 'string')]

# create empty dictonary to store output values

dict_count = {}

# Loop statement to count number of times the data type is present in the data frame

for x, y in datatypes_List:

    dict_count[y] = dict_count.get(y, 0) + 1

# query dict_count to find the number of times a data type is present in data frame

dict_count