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# EFILTER Forensic Query Language
#
# Copyright 2015 Google Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
EFILTER stdlib - IO module.
"""
__author__ = "Adam Sindelar <adamsh@google.com>"
import six
from efilter.ext import csv_reader
from efilter.protocols import repeated
from efilter.stdlib import core
class Lines(core.TypedFunction):
"""Return an IRepeated with lines from text file 'path'.
Arguments:
path: String with the path to the file to read in.
Raises:
IOError if the file can't be opened for whatever reason.
Returns:
An object implementing IRepeated containing the lines of in the file
as strings.
"""
name = "lines"
def __call__(self, path):
fd = open(path, "r")
# We don't close fd here, because repeated.lines is lazy and will read
# on demand. The descriptor will be closed in the repeated value's
# destructor.
return repeated.lines(fd)
@classmethod
def reflect_static_args(cls):
return (six.string_types[0],)
@classmethod
def reflect_static_return(cls):
return repeated.IRepeated
class CSV(core.TypedFunction):
"""Return an IRepeated with file at 'path' decoded as CSV.
Arguments:
path: Same as 'Lines'
decode_header: Use the first line in the file for column names and
return a dict per line, instead of tuple per line. (default: False.)
delim: Column separator (default: ",").
quote: Quote character (defalt: double quote).
trim: Eliminate leading whitespace (default: True).
Raises:
IOError if the file can't be opened for whatever reason.
Returns:
An IRepeated containing the lines in the CSV file decoded as either
a tuple of values per line, or a dict of values per line, if
'decode_header' is True.
"""
name = "csv"
def __call__(self, path, decode_header=False, delim=",", quote="\"",
trim=True):
fd = open(path, "r")
# We don't close fd here, because repeated.lines is lazy and will read
# on demand. The descriptor will be closed in the repeated value's
# destructor.
return csv_reader.LazyCSVReader(fd=fd, output_dicts=decode_header,
delim=delim, quote=quote, trim=trim)
@classmethod
def reflect_static_args(cls):
return (six.string_types[0], bool)
@classmethod
def reflect_static_return(cls):
return repeated.IRepeated
MODULE = core.LibraryModule(name="stdio",
vars={CSV.name: CSV(),
Lines.name: Lines()})
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