def getFirstAndMiddle(names): # Return a space separated string of names return ' '.join(names[:-1]) # Define the method as a UDF udfFirstAndMiddle = F.udf(getFirstAndMiddle, StringType()) # Create a new column
After running this code, you will see that the data type of the “age” column has been changed to IntegerType. This makes it easier to perform mathematical operations on the column. Another common scenario is converting a timestamp column to a date column. Let’s demonstrate this with anot...
问PySpark: TypeError: col应该是列ENSpark无疑是当今数据科学和大数据领域最流行的技术之一。尽管它是用...
在下一步中,我们创建一个 UDF (brand_udf),它使用这个函数并捕获它的数据类型,以便将这个转换应用到 dataframe 的移动列上。 [In]: brand_udf=udf(price_range,StringType()) 在最后一步,我们将udf(brand_udf)应用到 dataframe 的 mobile列,并创建一个具有新值的新列(price_range)。 [In]: df.withColumn...
# To convert the type of a column using the .cast() method, you can write code like this:dataframe=dataframe.withColumn("col",dataframe.col.cast("new_type"))# Cast the columns to integersmodel_data=model_data.withColumn("arr_delay",model_data.arr_delay.cast("integer"))model_data=model...
from pyspark.sql.typesimportIntegerType from pyspark.sql.functionsimportudf deffunc(fruit1,fruit2):iffruit1==None or fruit2==None:return3iffruit1==fruit2:return1return0func_udf=udf(func,IntegerType())df=df.withColumn('new_column',func_udf(df['fruit1'],df['fruit2'])) ...
df = df.withColumn("new_column", col("existing_column").cast("float")) 类型最好使用pyspark.sql.types中的数据类型此代码将 DataFrame df 中的名为 “existing_column” 的列的数据类型转换为浮点数,并将结果存储在名为 “new_column” 的新列中。需要注意的是,cast 函数只返回一个新的 DataFrame,它...
df.select(col("column_name").alias("new_column_name")) 2.字符串操作 concat:连接多个字符串。 substring:从字符串中提取子串。 trim:去除字符串两端的空格。 ltrim:去除字符串左端的空格。 rtrim:去除字符串右端的空格。 upper/lower:将字符串转换为大写/小写。
# Add a new key in the dictionary with the new column name and value. row_dict['Newcol'] = math.exp(row_dict['rating']) # convert dict to row: newrow = Row(**row_dict) # return new row return newrow # convert ratings dataframe to RDD ...
In some cases you may want to change the data type for one or more of the columns in your DataFrame. To do this, use the cast method to convert between column data types. The following example shows how to convert a column from an integer to string type, using the col method to ...