本机python-用于循环的数据帧并将记录插入到db

Question

I am working on AWS Glue, and so I cannot use Pandas/Numpy, etc currently.

I have a dataframe of records, which I need to process and update to mysql database. I need to check for record availability and already exists, do an insert...on duplicate key . For this reason, I need to loop through the dataframe using native python libraries. All dataframe iterators I found were using pandas, but is there a way to do without pandas?

Please find herewith a sample dataframe:

df1 = sqlContext.createDataFrame([
    ('4001','81A01','Portland, ME','NY'),
    ('4002','44444','Portland, ME','NY'),
    ('4022','33333','BANGALORE','KA'),
    ('5222','88888','CHENNAI','TN')],
    ("zip_code_new", "territory_code_new", "territory_name_new", "state_new"))

I tried the following, but i got an error message, " AttributeError: 'DataFrame' object has no attribute 'values' "

for i in df1.values():
    print i

UPDATE : The following code seem to work with native python to loop through the dataframe. Also, psidom's code also should work, but i could not see the print results.

arr = df1.collect()
  for r in arr:
      print r.zip_code_new

Thanks

Answer 1

You don't use for loop on spark data frame; It has foreach method to loop through rows; for example, we can print the zip_code_new in each row as follows:

def process_row(r):
    # your sql statement may go here
    print('zip_code_new: ', r.zip_code_new)

df1.foreach(process_row)

#('zip_code_new: ', u'4002')
#('zip_code_new: ', u'5222')
#('zip_code_new: ', u'4022')
#('zip_code_new: ', u'4001')