def upload_step_four(
request: http.HttpRequest,
workflow: models.Workflow,
upload_data: Dict,
) -> http.HttpResponse:
"""Perform the merge operation.
:param request: Received request
:param workflow: Workflow being processed
:param upload_data: Dictionary with all the information about the merge.
:return: HttpResponse
"""
# Get the dataframes to merge
try:
dst_df = pandas.load_table(workflow.get_data_frame_table_name())
src_df = pandas.load_table(workflow.get_upload_table_name())
except Exception:
return render(request, 'error.html',
{'message': _('Exception while loading data frame')})
try:
pandas.perform_dataframe_upload_merge(workflow, dst_df, src_df,
upload_data)
except Exception as exc:
# Nuke the temporary table
sql.delete_table(workflow.get_upload_table_name())
col_info = workflow.get_column_info()
workflow.log(request.user,
models.Log.WORKFLOW_DATA_FAILEDMERGE,
column_names=col_info[0],
column_types=col_info[1],
column_unique=col_info[2],
error_message=str(exc))
messages.error(request, _('Merge operation failed. ') + str(exc))
return redirect(reverse('table:display'))
col_info = workflow.get_column_info()
workflow.log(request.user,
upload_data['log_upload'],
column_names=col_info[0],
column_types=col_info[1],
column_unique=col_info[2])
store_workflow_in_session(request.session, workflow)
request.session.pop('upload_data', None)
return redirect(reverse('table:display'))
def upload_step_two(
request: http.HttpRequest,
workflow: models.Workflow,
select_column_data: Dict,
upload_data: Dict,
) -> http.HttpResponse:
"""Process the received dataframe and either store or continue merge.
:param request: Http request received.
:param workflow: workflow being processed.
:param select_column_data: Dictionary with the upload/merge information
(new column names, keep the keys)
:param upload_data: Dictionary with the upload information.
:return: Http Response
"""
# We need to modify upload_data with the information received in the
# post
initial_columns = upload_data.get('initial_column_names')
src_is_key_column = upload_data.get('src_is_key_column')
keep_key_column = upload_data.get('keep_key_column')
for idx in range(len(initial_columns)):
new_name = select_column_data['new_name_%s' % idx]
upload_data['rename_column_names'][idx] = new_name
upload = select_column_data['upload_%s' % idx]
upload_data['columns_to_upload'][idx] = upload
if src_is_key_column[idx]:
# If the column is key, check if the user wants to keep it
keep_key_column[idx] = select_column_data['make_key_%s' % idx]
if workflow.has_data_frame():
# A Merge operation is required
# Update the dictionary with the session information so that it is
# available in the next step
request.session['upload_data'] = upload_data
# This is a merge operation, so move to Step 3
return redirect('dataops:upload_s3')
# This is the first data to be stored in the workflow. Save the uploaded
# dataframe in the DB and finish.
pandas.store_workflow_table(workflow, upload_data)
# Update the session information
store_workflow_in_session(request.session, workflow)
col_info = workflow.get_column_info()
workflow.log(request.user,
upload_data['log_upload'],
column_names=col_info[0],
column_types=col_info[1],
column_unique=col_info[2])
return redirect(reverse('table:display'))
def batch_load_df_from_athenaconnection(
workflow: models.Workflow,
conn: models.AthenaConnection,
run_params: Dict,
log_item: models.Log,
):
"""Batch load a DF from an Athena connection.
run_params has:
aws_secret_access_key: Optional[str] = None,
aws_session_token: Optional[str] = None,
table_name: Optional[str] = None
key_column_name[str] = None
merge_method[str] = None
from pyathena import connect
from pyathena.pandas_cursor import PandasCursor
cursor = connect(
aws_access_key_id=aws_access_key_id,
aws_secret_access_key=aws_secret_access_key,
aws_session_token=aws_session_token,
s3_staging_dir=staging_dir,
region_name=region_name)
df = pd.read_sql('SELECT * FROM given_table_name', cursor)
print(df.describe())
print(df.head())
:param workflow: Workflow to store the new data
:param conn: AthenaConnection object with the connection parameters.
:param run_params: Dictionary with additional connection parameters
:param log_item: Log object to reflect the status of the execution
:return: Nothing.
"""
staging_dir = 's3://{0}'.format(conn.aws_bucket_name)
if conn.aws_file_path:
staging_dir = staging_dir + '/' + conn.aws_file_path
cursor = connect(aws_access_key_id=conn.aws_access_key,
aws_secret_access_key=run_params['aws_secret_access_key'],
aws_session_token=run_params['aws_session_token'],
s3_staging_dir=staging_dir,
region_name=conn.aws_region_name)
data_frame = pd.read_sql_table(run_params['table_name'], cursor)
# Strip white space from all string columns and try to convert to
# datetime just in case
data_frame = pandas.detect_datetime_columns(data_frame)
pandas.verify_data_frame(data_frame)
col_names, col_types, is_key = pandas.store_temporary_dataframe(
data_frame, workflow)
upload_data = {
'initial_column_names': col_names,
'col_types': col_types,
'src_is_key_column': is_key,
'rename_column_names': col_names[:],
'columns_to_upload': [True] * len(col_names),
'keep_key_column': is_key[:]
}
if not workflow.has_data_frame():
# Regular load operation
pandas.store_workflow_table(workflow, upload_data)
log_item.payload['col_names'] = col_names
log_item.payload['col_types'] = col_types
log_item.payload['column_unique'] = is_key
log_item.payload['num_rows'] = workflow.nrows
log_item.payload['num_cols'] = workflow.ncols
log_item.save(update_fields=['payload'])
return
# Merge operation
upload_data['dst_column_names'] = workflow.get_column_names()
upload_data['dst_is_unique_column'] = workflow.get_column_unique()
upload_data['dst_unique_col_names'] = [
cname for idx, cname in enumerate(upload_data['dst_column_names'])
if upload_data['dst_column_names'][idx]
]
upload_data['src_selected_key'] = run_params['merge_key']
upload_data['dst_selected_key'] = run_params['merge_key']
upload_data['how_merge'] = run_params['merge_method']
dst_df = pandas.load_table(workflow.get_data_frame_table_name())
src_df = pandas.load_table(workflow.get_data_frame_upload_table_name())
try:
pandas.perform_dataframe_upload_merge(workflow, dst_df, src_df,
upload_data)
except Exception as exc:
# Nuke the temporary table
sql.delete_table(workflow.get_data_frame_upload_table_name())
raise Exception(
_('Unable to perform merge operation: {0}').format(str(exc)))
col_names, col_types, is_key = workflow.get_column_info()
log_item.payload['col_names'] = col_names
log_item.payload['col_types'] = col_types
log_item.payload['column_unique'] = is_key
log_item.payload['num_rows'] = workflow.nrows
log_item.payload['num_cols'] = workflow.ncols
log_item.save(update_fields=['payload'])
