6. Using PGQL results¶
Retrieving results after executing a PGQL query can be done using the following methods of the PgqlResultSet class.
Please note that this functionality is different from the one included in OPG4Py package. For more details look into the PGQL documentation.
- class pypgx.api.PgqlResultSet(graph, java_pgql_result_set)
Result set of a pattern matching query.
Note: retrieving results from the server is not thread-safe.
- absolute(row)
Move the cursor to the given row number in this ResultSet object.
If the row number is positive, the cursor moves to the given row number with respect to the beginning of the result set. The first row is 1, so absolute(1) moves the cursor to the first row.
If the row number is negative, the cursor moves to the given row number with respect to the end of the result set. So absolute(-1) moves the cursor to the last row.
- Parameters
row – Row to move to
- Returns
True if the cursor is moved to a position in the ResultSet object;
False if the cursor is moved before the first or after the last row
- after_last()
Place the cursor after the last row
- before_first()
Set the cursor before the first row
- close()
Free resources on the server taken up by this frame.
- destroy()
Free resources on the server taken up by this frame.
- first()
Move the cursor to the first row in the result set
- Returns
True if the cursor points to a valid row; False if the result set does not
have any results
- get(element)
Get the value of the designated element by element index or name
- Parameters
element – Integer or string representing index or name
- Returns
Content of cell
- get_boolean(element)
Get the value of the designated element by element index or name as a Boolean
- Parameters
element – Integer or String representing index or name
- Returns
Boolean
- get_date(element)
Get the value of the designated element by element index or name as a datetime Date
- Parameters
element – Integer or String representing index or name
- Returns
datetime.date
- get_double(element)
Get the value of the designated element by element index or name as a Float
This method is for precision, as a Java floats and doubles have different precisions
- Parameters
element – Integer or String representing index or name
- Returns
Float
- get_edge(element)
Get the value of the designated element by element index or name as a PgxEdge
- Parameters
element – Integer or String representing index or name
- Returns
PgxEdge
- get_float(element)
Get the value of the designated element by element index or name as a Float
- Parameters
element – Integer or String representing index or name
- Returns
Float
- get_integer(element)
Get the value of the designated element by element index or name as an Integer
- Parameters
element – Integer or String representing index or name
- Returns
Integer
- get_legacy_datetime(element)
Get the value of the designated element by element index or name as a Datetime. Works with most time and date type cells. If the date is not specified, default is set to to Jan 1 1970.
- Parameters
element – Integer or String representing index or name
- Returns
datetime.datetime
- get_list(element)
Get the value of the designated element by element index or name as a List
- Parameters
element – Integer or String representing index or name
- Returns
List
- get_long(element)
Get the value of the designated element by element index or name as a Long
- Parameters
element – Integer or String representing index or name
- Returns
Long
- get_point2d(element)
Get the value of the designated element by element index or name as a 2D tuple
- Parameters
element – Integer or String representing index or name
- Returns
(X, Y)
- get_row(row)
Get row from result_set. This method may change result_set cursor.
- Parameters
row – Row index
- get_slice(start, stop, step=1)
Get slice from result_set. This method may change result_set cursor.
- Parameters
start – Start index
stop – Stop index
step – Step size
- get_string(element)
Get the value of the designated element by element index or name as a String
- Parameters
element – Integer or String representing index or name
- Returns
String
- get_time(element)
Get the value of the designated element by element index or name as a datetime Time
- Parameters
element – Integer or String representing index or name
- Returns
datetime.time
- get_time_with_timezone(element)
Get the value of the designated element by element index or name as a datetime Time that includes timezone
- Parameters
element – Integer or String representing index or name
- Returns
datetime.time
- get_timestamp(element)
Get the value of the designated element by element index or name as a Datetime
- Parameters
element – Integer or String representing index or name
- Returns
datetime.datetime
- get_timestamp_with_timezone(element)
Get the value of the designated element by element index or name as a Datetime
- Parameters
element – Integer or String representing index or name
- Returns
datetime.datetime
- get_vertex(element)
Get the value of the designated element by element index or name as a PgxVertex
- Parameters
element – Integer or String representing index or name
- Returns
PgxVertex
- get_vertex_labels(element)
Get the value of the designated element by element index or name a list of labels
- Parameters
element – Integer or String representing index or name
- Returns
list
- last()
Move the cursor to the first row in the result set
- Returns
True if the cursor points to a valid row; False if the result set does not
have any results
- next()
Move the cursor forward one row from its current position
- Returns
True if the cursor points to a valid row; False if the new cursor is positioned
after the last row
- previous()
Move the cursor to the previous row from its current position
- Returns
True if the cursor points to a valid row; False if the new cursor is positioned
before the first row
- print(file=None, num_results=1000, start=0)
Print the result set.
- Parameters
file – File to which results are printed (default is
sys.stdout)num_results – Number of results to be printed
start – Index of the first result to be printed
- relative(rows)
Move the cursor a relative number of row with respect to the current position. A negative number will move the cursor backwards.
Note: Calling relative(1) is equal to next() and relative(-1) is equal to previous. Calling relative(0) is possible when the cursor is positioned at a row, not when it is positioned before the first or after the last row. However, relative(0) will not update the position of the cursor.
- Parameters
rows – Relative number of rows to move from current position
- Returns
True if the cursor is moved to a position in the ResultSet object; False if
the cursor is moved before the first or after the last row
- to_frame()
Copy the content of this result set into a new PgxFrames
- Returns
a new PgxFrame containing the content of the result set
- to_pandas()
Convert to pandas DataFrame.
This method may change result_set cursor.
This method requires pandas.
- Returns
PgqlResultSet as a Pandas Dataframe