https://github.com/mezantrop/tsqlike
SQL-like interface to tabular structured data
https://github.com/mezantrop/tsqlike
csv data-processing data-structures json python sql-like table
Last synced: 4 months ago
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SQL-like interface to tabular structured data
- Host: GitHub
- URL: https://github.com/mezantrop/tsqlike
- Owner: mezantrop
- License: bsd-2-clause
- Created: 2024-06-06T08:40:42.000Z (almost 2 years ago)
- Default Branch: main
- Last Pushed: 2024-11-01T17:14:00.000Z (over 1 year ago)
- Last Synced: 2025-05-07T06:43:32.600Z (about 1 year ago)
- Topics: csv, data-processing, data-structures, json, python, sql-like, table
- Language: Python
- Homepage:
- Size: 134 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
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README
# tSQLike
[](https://github.com/mezantrop/tSQLike/actions/workflows/python-package.yml)
[](https://github.com/mezantrop/tSQLike/actions/workflows/codeql.yml)
## SQL-like interface to tabular structured data
## Description
**tSQLike** is a `Python3` module that is written with a hope to make tabular data processing easier using SQL-like primitives.
## Notes
**Not that early stage, but still in development: may contain bugs**
## Usage
```Python3
import tsqlike
t1 = tsqlike.Table(data=[['h1', 'h2', 'h3', 'h4'],
['a', 'b', 'c', 'd'],
['b', 'c', 'd', 'd'],
['f', 'g', 'h', 'i']],
name='first')
t2 = tsqlike.Table().import_list_dicts(data=[{'h1': 1, 'h2': 2, 'h3': 3},
{'h1': 'd', 'h2': 'e', 'h3': 'f'}],
name='second')
t3 = t1.join(t2, on='first.h4 == second.h1').select('*').order_by('second.h2', direction=tsqlike.ORDER_BY_DEC)
t3.write_csv(dialect='unix')
"first.h1", "first.h2", "first.h3", "first.h4", "second.h1", "second.h2", "second.h3"
"b", "c", "d", "d", "d", "e", "f"
"a", "b", "c", "d", "d", "e", "f"
```
## Installation
```sh
pip install tsqlike
```
## Functionality
### Table class
The main class of the module
#### Data processing methods
| Name | Status | Description |
|-------------|---------|--------------------------------------------------------------------------------------------|
| `column_map`| ☑ | Apply a function to a column |
| `join` | ☑ | Join two Tables (`self` and `table`) on an expression [*](#Warning). Complex, but **slow** |
| `join_lt` | ☑ | Light, limited, **fast** and safe `Join`, that doesn't use `eval()` |
| `select` | ☑ | Select column(s) from the `Table` [*](#Warning) |
| `select_lt` | ☑ | `eval()`-free version of select |
| `order_by` | ☑ | ORDER BY primitive of SQL SELECT to sort the Table by a column |
| `group_by` | ☑ | GROUP BY primitive of SQL SELECT to apply aggregate function on a column |
#### Import methods
| Name | Status | Description |
|---------------------|---------|-------------------------------------------------------------------------|
| `import_dict_lists` | ☑ | Import a dictionary of lists into Table object |
| `import_list_dicts` | ☑ | Import a list of horizontal arranged dictionaries into the `Table` |
| `import_list_lists` | ☑ | Import `list(list_1(), list_n())` with optional first row as the header |
#### Export methods
| Name | Status | Description |
|---------------------|---------|-------------------------------------------------------------------------|
| `export_dict_lists` | ☑ | Export a dictionary of lists |
| `export_list_dicts` | ☑ | Export list of dictionaries |
| `export_list_lists` | ☑ | Export `list(list_1(), list_n())` with optional first row as the header |
#### Write methods
| Name | Status | Description |
|-----------------|---------|---------------------------------------------------------------------|
| `write_csv` | ☑ | Make `CSV` from the `Table` object and write it to a file or stdout |
| `write_json` | ☑ | Write `JSON` into file or `STDOUT` [*](#Warning) |
| `write_json_lt` | ☑ | `eval()`-free version of `Table.write_json` |
| `write_xml` | ☐ | Write `XML`. NB: Do we need this? |
#### Header manipulation methods
| Name | Status | Description |
|-------------------|---------|----------------------------------------------------------------------------|
| `get_column` | ☑ | Return either a column name by index or index by name. None if not found |
| `rename_column` | ☑ | Rename a column name in the header |
| `make_shortnames` | ☑ | Return Header with no Dot-prefix of the columns |
| `set_shortnames` | ☑ | Remove Dot-prefix of the columns from self/Table header |
#### Private methods
| Name | Status | Description |
|----------------|---------|-------------------------------------------|
| `_redimension` | ☑ | Recalculate dimensions of the Table.table |
### EvalCtrl class
Controls what arguments are available to `eval()` function
| Name | Status | Description |
|--------------------|---------|----------------------------------------------------------|
| `blacklisted` | ☑ | Checks if there is any of the blacklised words in stanza |
| `blacklist_add` | ☑ | Add a new word into the black list |
| `blacklist_remove` | ☑ | Remove the word from the blacklist |
### Standalone functions
| Name | Status | Description |
|---------------|---------|------------------------------------------------------------|
| `open_file` | ☑ | Open a file |
| `close_file` | ☑ | Close a file |
| `read_json` | ☑ | Read `JSON` file |
| `read_csv` | ☑ | Read `CSV` file |
| `read_xml` | ☐ | Read `XML`. NB: Do we need XML support? |
| `str_to_type` | ☑ | Convert a `str` to a proper type: `int`, `float` or `bool` |
#### WARNING
Methods `Table.join(on=)`, `Table.select(where=)` and `Table.write_json(export_f=)`, use `eval()` function
to run specified expressions within the program. **ANY** expression, including one that is potentially **DANGEROUS**
from security point of view, can be passed as the values of the above arguments. It is your duty to ensure correctness
and safety of these arguments and `EvalCtrl` helps to block potentially dangerous function/method names.
Alternatively you can use `Table.join_lt()`, `Table.select_lt()` and `Table.write_json()`. They are significantly less
powerful, but do not use `eval()`.
## TODO
* Rework: Table Names, Header Column Names, Dot-Prefixes
* Documentation!
## Contacts
If you have an idea, a question, or have found a problem, do not hesitate to open an issue or mail me directly:
Mikhail Zakharov