ConvUtils 1.1

A library of convenient utility functions and pure Python data structures.

ConvUtils provides a small library of convenience functions for dealing with a variety of tasks, such as creating CSV readers and writers, and convenient data structures, such as a two-way dictionary.

This package provides two modules: convutils and convstructs. Typically, the user will want to import one or the other, e.g.:

from convutils import convutils

convutils

convutils provides the following classes:

• ExcelTabNewlineDialect is similar to the csv.excel_tab dialect, but uses the newline character ('\n') as the line separator, giving a more Unix-friendly tsv (tab-separated values) format.

convutils also provides the following functions:

• make_csv_reader creates a csv.DictReader or csv.Reader instance with the convenience of the user not having to explicitly specify the CSV dialect.

• make_csv_dict_writer creates a csv.DictWriter instance with the convenience of not having to manually enter the header row yourself; uses ExcelTabNewlineDialect as the dialect, by default.

• append_to_file_base_name will return a modified file name given an original one and a string between the base name and the extension (e.g., append_to_file_base_name('myfile.txt', '-2') returns 'myfile-2.txt').

• count_lines counts the number of lines in a file.

• split_file_by_parts takes one large file and splits it into new files, the maximum number of which is given by the user.

• split_file_by_num_lines takes one large file and splits it into new file, the maximum number of lines in each being defined by the user.

• column_args_to_indices takes a string representing desired columns (e.g., '1-4,6,8') and converts it into actual indices and slices of an indexable Python sequence.

• cumsum produces the cumulative sum of any iterable whose elements support the add operator. (New in version 1.1.)

• sample_list_dict is like random.sample but for dictionaries whose values are lists or other enumerable, iterable container types. (New in version 1.1.)

• sample_list_dict_low_mem is similar to sample_list_dict but has a lower memory consumption for larger dictionaries. (New in version 1.1.)

convstructs

convstructs provides two convenient data structures, both specialized subclasses of Python’s dict.

• SortedTupleKeysDict is a dictionary which expects 2-tuples as keys, and will always sort the tuples, either when setting or retrieving values.

• TwoWaySetDict is a dictionary that assumes the values are sets, and will store a reverse lookup dictionary to tell you, for each set in the values that some item belongs to, the keys with which item is associated.

Installation

Installation is easy with pip; simply run

pip install ConvUtils

Availability

• PyPI page: http://pypi.python.org/pypi/ConvUtils/

• GitHub project page: https://github.com/gotgenes/python-ConvUtils