# ==============================================================================
# CSVReport.py - Python wrapper for IDM csv report files
# ==============================================================================
"""CVSReport.py
This class is a simple Python wrapper for csv report files.
Usage::
report = CSVReport(path.combine(my_dir, "ReportEventRecorder.csv"))
print report
"""
# imports
from builtins import range
from builtins import object
import csv
import sys
# ==============================================================================
# CSVReport - a class to hold IDM csv report files
# ==============================================================================
[docs]class CSVReport(object):
"""Class to hold DTK CSV report data.
The class is constructed with the path to the report file in question.
Thereafter the public data members source_file and rows may be used to
directly access the resultant Python representation of the file.
Additionally, since CSVReport implements __len__ and __iter__, the report
object can be treated like a list, e.g.::
row = report[10] # Obtain the 11th row
Public members:
The following data members are publicly exposed.
source_file (str): A copy of the file_path that was used to construct
the CSVReport object.
rows (array): Array of Python objects made from the input file lines.
header (array): Array of field names read from top of CSV file.
"""
def __init__(self, file_path="", verbose=False):
"""Construct a CSVReport.
Args:
file_path (str): The path to the CSV report file.
verbose (bool): True for extra message from methods.
Raises:
I/O or csv exceptions.
"""
# data members
self.source_file = ""
self.rows = []
self.header = []
self._verbose = verbose
# read if file path was given
if not file_path == "":
self._read_csv(file_path)
# --------------------------------------------------------------------------
def __str__(self):
"""Generates a textual representation of a CSVReport.
This method allows the CSVReport object to report the source
file and number of rows when it is printed.
Returns:
str: String containing source file and row count.
"""
if len(self.rows) == 0:
return "(empty)"
else:
return self.source_file + ": " + repr(len(self.rows)) + " rows"
# --------------------------------------------------------------------------
def __len__(self):
"""Returns the number of rows read from the CSV report.
Returns:
int: Number of rows in CSV report.
"""
return len(self.rows)
# --------------------------------------------------------------------------
def __iter__(self):
"""Returns an iterator for the CSV rows.
Returns:
iterator: Iterator for CSV report rows.
"""
return self.rows.__iter__()
# --------------------------------------------------------------------------
def __getitem__(self, index):
"""Returns the indexed item.
Returns:
obj: Record for row index.
Args:
index (int): Desired row index.
Raises:
Data access exceptions.
"""
return self.rows[index]
# --------------------------------------------------------------------------
[docs] def make_series(self, name, time_field, data_field):
"""Make a Highcharts-compatible series object from CSV rows.
Returns:
obj: Object for use as a Highcharts data series.
Args:
name (str): The name that is put into the output series structure.
time_field (str): The column name for the column representing time.
data_field (str): The column name for teh data (Y) value.
Raises:
Data access exceptions.
"""
result = {
"name": name,
"data": []
}
if len(self.rows) == 0 and self._verbose:
print("CSVReport.make_series called but no rows present",
file=sys.stderr)
for row in self.rows:
result["data"].append(
[int(row[time_field]), float(row[data_field])])
return result
# --------------------------------------------------------------------------
[docs] def read_partial(self, file_path, row_count):
"""Read the first row_count rows off a CSV.
To do a partial read of a CSV report, create a CSVReport with the
default constructor, then call read_partial to read as many rows as
desired. E.g.::
report = CSVReport()
report.read_partial(my_csv_file_path, 100)
print report.rows[10]
Returns:
None.
Args:
file_path (str): File path of CSV report.
row_count: The number of rows to read.
Raises:
I/O, csv exceptions.
"""
self.source_file = file_path
self._read_csv_partial(file_path, row_count)
# --------------------------------------------------------------------------
[docs] def missing_columns(self, column_list):
"""Confirms that a given set of columns exists in a CSVReport.
This function can be used to verify the presence of a set of
(presumably required) fields in a CSVReport. Typical usage is::
if (rpt.missing_columns(["Time", "Node_ID"]) is None)
# All require columns present, so carry on
Returns:
List of columns from column_list that are not present, or None if
all columns are present.
Args:
column_list (list): Columns to be tested for.
"""
if len(self.header) == 0:
return column_list # Probably nothing was read
result = [column for column in column_list if column not in self.header]
return result if len(result) > 0 else None
# --------------------------------------------------------------------------
# Implementation
# --------------------------------------------------------------------------
def _read_csv(self, csv_file_path):
try:
with open(csv_file_path, "r") as csv_file:
# the following is required because some CSVs generated by the
# reporters have Spaces, In, The, Header, Line.
# Also, they have "Double", "Quotes" so we strip that too.
line = csv_file.readline().strip()
self.header = [h.strip().replace('"', '')
for h in line.split(',')]
reader = csv.DictReader(csv_file, fieldnames=self.header)
self.source_file = csv_file_path
self.rows = []
for row in reader:
self.rows.append(row)
except BaseException:
if self._verbose:
print("CSVReport._read_csv: Exception %s reading CSV" %
sys.exc_info[0], file=sys.stderr)
raise
# --------------------------------------------------------------------------
def _read_csv_partial(self, csv_file_path, row_count):
try:
with open(csv_file_path, "r") as csv_file:
# the following is required because some CSVs generated by the
# reporters have Spaces, In, The, Header, Line.
# Also, they have "Double", "Quotes" so we strip that too.
line = csv_file.readline().strip()
self.header = [h.strip().replace('"', '')
for h in line.split(',')]
reader = csv.DictReader(csv_file, fieldnames=self.header)
self.source_file = csv_file_path
self.rows = []
for row_num in range(0, row_count):
row = next(reader, None)
if row is None:
break
else:
self.rows.append(row)
except BaseException:
if self._verbose:
print("CSVReport._read_csv_partial: Exception %s partial-"
"reading CSV" % sys.exc_info[0], file=sys.stderr)
raise
