pcsv 1.0.8

Description:

pcsv 1.0.8

Description
This module can be used to handle comma-separated values (CSV) files and do
lightweight processing of their data with support for row and column
filtering. In addition to basic read, write and data replacement, files can be
concatenated, merged, and sorted

Examples

Read/write
# pcsv_example_1.py
import pmisc, pcsv

def main():
with pmisc.TmpFile() as fname:
ref_data = [["Item", "Cost"], [1, 9.99], [2, 10000], [3, 0.10]]
# Write reference data to a file
pcsv.write(fname, ref_data, append=False)
# Read the data back
obj = pcsv.CsvFile(fname)
# After the object creation the I/O is done,
# can safely remove file (exit context manager)
# Check that data read is correct
assert obj.header() == ref_data[0]
assert obj.data() == ref_data[1:]
# Add a simple row filter, only look at rows that have
# values 1 and 3 in the "Items" column
obj.rfilter = {"Item": [1, 3]}
assert obj.data(filtered=True) == [ref_data[1], ref_data[3]]

if __name__ == "__main__":
main()


Replace data
# pcsv_example_2.py
import pmisc, pcsv

def main():
ctx = pmisc.TmpFile
with ctx() as fname1:
with ctx() as fname2:
with ctx() as ofname:
# Create first (input) data file
input_data = [["Item", "Cost"], [1, 9.99], [2, 10000], [3, 0.10]]
pcsv.write(fname1, input_data, append=False)
# Create second (replacement) data file
replacement_data = [
["Staff", "Rate", "Days"],
["Joe", 10, "Sunday"],
["Sue", 20, "Thursday"],
["Pat", 15, "Tuesday"],
]
pcsv.write(fname2, replacement_data, append=False)
# Replace "Cost" column of input file with "Rate" column
# of replacement file for "Items" 2 and 3 with "Staff" data
# from Joe and Pat. Save resulting data to another file
pcsv.replace(
fname1=fname1,
dfilter1=("Cost", {"Item": [1, 3]}),
fname2=fname2,
dfilter2=("Rate", {"Staff": ["Joe", "Pat"]}),
ofname=ofname,
)
# Verify that resulting file is correct
ref_data = [["Item", "Cost"], [1, 10], [2, 10000], [3, 15]]
obj = pcsv.CsvFile(ofname)
assert obj.header() == ref_data[0]
assert obj.data() == ref_data[1:]

if __name__ == "__main__":
main()


Concatenate two files
# pcsv_example_3.py
import pmisc, pcsv

def main():
ctx = pmisc.TmpFile
with ctx() as fname1:
with ctx() as fname2:
with ctx() as ofname:
# Create first data file
data1 = [[1, 9.99], [2, 10000], [3, 0.10]]
pcsv.write(fname1, data1, append=False)
# Create second data file
data2 = [
["Joe", 10, "Sunday"],
["Sue", 20, "Thursday"],
["Pat", 15, "Tuesday"],
]
pcsv.write(fname2, data2, append=False)
# Concatenate file1 and file2. Filter out
# second column of file2
pcsv.concatenate(
fname1=fname1,
fname2=fname2,
has_header1=False,
has_header2=False,
dfilter2=[0, 2],
ofname=ofname,
ocols=["D1", "D2"],
)
# Verify that resulting file is correct
ref_data = [
["D1", "D2"],
[1, 9.99],
[2, 10000],
[3, 0.10],
["Joe", "Sunday"],
["Sue", "Thursday"],
["Pat", "Tuesday"],
]
obj = pcsv.CsvFile(ofname)
assert obj.header() == ref_data[0]
assert obj.data() == ref_data[1:]

if __name__ == "__main__":
main()


Merge two files
# pcsv_example_4.py
import pmisc, pcsv

def main():
ctx = pmisc.TmpFile
with ctx() as fname1:
with ctx() as fname2:
with ctx() as ofname:
# Create first data file
data1 = [[1, 9.99], [2, 10000], [3, 0.10]]
pcsv.write(fname1, data1, append=False)
# Create second data file
data2 = [
["Joe", 10, "Sunday"],
["Sue", 20, "Thursday"],
["Pat", 15, "Tuesday"],
]
pcsv.write(fname2, data2, append=False)
# Merge file1 and file2
pcsv.merge(
fname1=fname1,
has_header1=False,
fname2=fname2,
has_header2=False,
ofname=ofname,
)
# Verify that resulting file is correct
ref_data = [
[1, 9.99, "Joe", 10, "Sunday"],
[2, 10000, "Sue", 20, "Thursday"],
[3, 0.10, "Pat", 15, "Tuesday"],
]
obj = pcsv.CsvFile(ofname, has_header=False)
assert obj.header() == list(range(0, 5))
assert obj.data() == ref_data

if __name__ == "__main__":
main()


Sort a file
# pcsv_example_5.py
import pmisc, pcsv

def main():
ctx = pmisc.TmpFile
with ctx() as ifname:
with ctx() as ofname:
# Create first data file
data = [
["Ctrl", "Ref", "Result"],
[1, 3, 10],
[1, 4, 20],
[2, 4, 30],
[2, 5, 40],
[3, 5, 50],
]
pcsv.write(ifname, data, append=False)
# Sort
pcsv.dsort(
fname=ifname,
order=[{"Ctrl": "D"}, {"Ref": "A"}],
has_header=True,
ofname=ofname,
)
# Verify that resulting file is correct
ref_data = [[3, 5, 50], [2, 4, 30], [2, 5, 40], [1, 3, 10], [1, 4, 20]]
obj = pcsv.CsvFile(ofname, has_header=True)
assert obj.header() == ["Ctrl", "Ref", "Result"]
assert obj.data() == ref_data

if __name__ == "__main__":
main()




Interpreter
The package has been developed and tested with Python 2.7, 3.5, 3.6 and 3.7
under Linux (Debian, Ubuntu), Apple macOS and Microsoft Windows


Installing
$ pip install pcsv


Documentation
Available at Read the Docs


Contributing

Abide by the adopted code of conduct
Fork the repository from GitHub and
then clone personal copy [1]:

$ github_user=myname
$ git clone --recurse-submodules \
https://github.com/"${github_user}"/pcsv.git
Cloning into 'pcsv'...
...
$ cd pcsv || exit 1
$ export PCSV_DIR=${PWD}
$


The package uses two sub-modules: a set of custom Pylint plugins to help with
some areas of code quality and consistency (under the pylint_plugins
directory), and a lightweight package management framework (under the
pypkg directory). Additionally, the pre-commit framework is used to perform various pre-commit code
quality and consistency checks. To enable the pre-commit hooks:

$ cd "${PCSV_DIR}" || exit 1
$ pre-commit install
pre-commit installed at .../pcsv/.git/hooks/pre-commit
$


Ensure that the Python interpreter can find the package modules
(update the $PYTHONPATH environment variable, or use
sys.paths(),
etc.)
$ export PYTHONPATH=${PYTHONPATH}:${PCSV_DIR}
$

Install the dependencies (if needed, done automatically by pip):


Cog (2.5.1 or newer)
Coverage (4.5.3 or newer)
Docutils (0.14 or newer)
Inline Syntax Highlight Sphinx Extension (0.2 or newer)
Mock (Python 2.x only, 2.0.0 or newer)
Pexdoc (1.1.4 or newer)
Pmisc (1.5.8 or newer)
Py.test (4.3.1 or newer)
PyContracts (1.8.2 or newer)
Pydocstyle (3.0.0 or newer)
Pylint (Python 2.x: 1.9.4 or newer, Python 3.x: 2.3.1 or newer)
Pytest-coverage (2.6.1 or newer)
Pytest-pmisc (1.0.7 or newer)
Pytest-xdist (optional, 1.26.1 or newer)
ReadTheDocs Sphinx theme (0.4.3 or newer)
Shellcheck Linter Sphinx Extension (1.0.8 or newer)
Sphinx (1.8.5 or newer)
Tox (3.7.0 or newer)
Virtualenv (16.4.3 or newer)



Implement a new feature or fix a bug
Write a unit test which shows that the contributed code works as expected.
Run the package tests to ensure that the bug fix or new feature does not
have adverse side effects. If possible achieve 100% code and branch
coverage of the contribution. Thorough package validation
can be done via Tox and Pytest:
$ PKG_NAME=pcsv tox
GLOB sdist-make: .../pcsv/setup.py
py27-pkg create: .../pcsv/.tox/py27
py27-pkg installdeps: -r.../pcsv/requirements/tests_py27.pip, -r.../pcsv/requirements/docs_py27.pip
...
py27-pkg: commands succeeded
py35-pkg: commands succeeded
py36-pkg: commands succeeded
py37-pkg: commands succeeded
congratulations :)
$
Setuptools can also be used
(Tox is configured as its virtual environment manager):
$ PKG_NAME=pcsv python setup.py tests
running tests
running egg_info
writing pcsv.egg-info/PKG-INFO
writing dependency_links to pcsv.egg-info/dependency_links.txt
writing requirements to pcsv.egg-info/requires.txt
...
py27-pkg: commands succeeded
py35-pkg: commands succeeded
py36-pkg: commands succeeded
py37-pkg: commands succeeded
congratulations :)
$
Tox (or Setuptools via Tox) runs with the following default environments:
py27-pkg, py35-pkg, py36-pkg and py37-pkg [3]. These use
the 2.7, 3.5, 3.6 and 3.7 interpreters, respectively, to test all code in
the documentation (both in Sphinx *.rst source files and in
docstrings), run all unit tests, measure test coverage and re-build the
exceptions documentation. To pass arguments to Pytest (the test runner) use
a double dash (--) after all the Tox arguments, for example:
$ PKG_NAME=pcsv tox -e py27-pkg -- -n 4
GLOB sdist-make: .../pcsv/setup.py
py27-pkg inst-nodeps: .../pcsv/.tox/.tmp/package/1/pcsv-1.0.8.zip
...
py27-pkg: commands succeeded
congratulations :)
$
Or use the -a Setuptools optional argument followed by a quoted
string with the arguments for Pytest. For example:
$ PKG_NAME=pcsv python setup.py tests -a "-e py27-pkg -- -n 4"
running tests
...
py27-pkg: commands succeeded
congratulations :)
$
There are other convenience environments defined for Tox [3]:


py27-repl, py35-repl, py36-repl and py37-repl run the
Python 2.7, 3.5, 3.6 and 3.7 REPL, respectively, in the appropriate
virtual environment. The pcsv package is pip-installed by Tox when
the environments are created. Arguments to the interpreter can be
passed in the command line after a double dash (--).
py27-test, py35-test, py36-test and py37-test run Pytest
using the Python 2.7, 3.5, 3.6 and 3.7 interpreter, respectively, in the
appropriate virtual environment. Arguments to pytest can be passed in
the command line after a double dash (--) , for example:
$ PKG_NAME=pcsv tox -e py27-test -- -x test_pcsv.py
GLOB sdist-make: .../pcsv/setup.py
py27-pkg inst-nodeps: .../pcsv/.tox/.tmp/package/1/pcsv-1.0.8.zip
...
py27-pkg: commands succeeded
congratulations :)
$

py27-test, py35-test, py36-test and py37-test test code
and branch coverage using the 2.7, 3.5, 3.6 and 3.7 interpreter,
respectively, in the appropriate virtual environment. Arguments to
pytest can be passed in the command line after a double dash (--).
The report can be found in
${PCSV_DIR}/.tox/py[PV]/usr/share/pcsv/tests/htmlcov/index.html
where [PV] stands for 2.7, 3.5, 3.6 or 3.7 depending
on the interpreter used.



Verify that continuous integration tests pass. The package has continuous
integration configured for Linux, Apple macOS and Microsoft Windows (all via
Azure DevOps).
Document the new feature or bug fix (if needed). The script
${PCSV_DIR}/pypkg/build_docs.py re-builds the whole package
documentation (re-generates images, cogs source files, etc.):
$ "${PCSV_DIR}"/pypkg/build_docs.py -h
usage: build_docs.py [-h] [-d DIRECTORY] [-r]
[-n NUM_CPUS] [-t]

Build pcsv package documentation

optional arguments:
-h, --help show this help message and exit
-d DIRECTORY, --directory DIRECTORY
specify source file directory
(default ../pcsv)
-r, --rebuild rebuild exceptions documentation.
If no module name is given all
modules with auto-generated
exceptions documentation are
rebuilt
-n NUM_CPUS, --num-cpus NUM_CPUS
number of CPUs to use (default: 1)
-t, --test diff original and rebuilt file(s)
(exit code 0 indicates file(s) are
identical, exit code 1 indicates
file(s) are different)


Footnotes


[1]
All examples are for the bash
shell


[2]
It is assumed that all the Python interpreters are in the executables
path. Source code for the interpreters can be downloaded from Python’s main
site


[3]
(1,2)
Tox configuration largely inspired by
Ionel’s codelog




License
The MIT License (MIT)
Copyright (c) 2013-2019 Pablo Acosta-Serafini
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the “Software”), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
.. CHANGELOG.rst
.. Copyright (c) 2013-2019 Pablo Acosta-Serafini
.. See LICENSE for details


Changelog

1.0.8 [2019-03-22]: Documentation and dependency update
1.0.7 [2019-03-09]: Dropped support for Python 2.6, 3.3 and 3.4. Updates to
support newest versions of dependencies. Adopted lightweight package
management framework
1.0.6 [2017-09-10]: Fixed bug while filtering rows that have empty column
specified in filter. Fixed broken multi-line links in documentation
1.0.5 [2017-02-10]: Package build enhancements and fixes
1.0.4 [2017-02-07]: Python 3.6 support
1.0.3 [2016-06-10]: Minor documentation build bug fix
1.0.2 [2016-05-12]: Minor documentation updates
1.0.1 [2016-05-12]: Minor documentation updates
1.0.0 [2016-05-12]: Final release of 1.0.0 branch
1.0.0rc1 [2016-05-11]: Initial commit, forked a subset from putil PyPI
package