`infoml.utils`

This module contains utility functions for the infoml package. Some of these functions are modified from the bmes package by Dr. Ahmet Sacan.

Module Contents

Classes

SQLite

Wrapper for connecting to and querying SQLite databases

Functions

`ispc`(→ bool)	Check if the current platform is Windows
`isnonemptydir`(→ bool)	Check if a directory is non-empty
`isnonemptyfile`(→ bool)	Check if a file is non-empty
`slugify`(→ str)	Convert a string to a slug
`downloadurl`(, overwrite, progress)	Download and save file from a given URL
`iohead`(→ None)	Print the first n rows of a text file
`system`(→ str)	Run a system command; allows you to redirect stdout and stderr.

infoml.utils.ispc() → bool[source]: Check if the current platform is Windows

infoml.utils.isnonemptydir(path: Path | str) → bool[source]: Check if a directory is non-empty

infoml.utils.isnonemptyfile(path: Path | str) → bool[source]: Check if a file is non-empty

infoml.utils.slugify(text: str, allow_unicode: bool = False) → str[source]

Convert a string to a slug

Based on Django’s slugify function 1. This function converts a string to a slug. A slug is a string that contains only letters, numbers, underscores or hyphens. It is typically used to generate URL-friendly strings.

Parameters

text (str) – The string to be sluggified
allow_unicode (bool, optional) – Should unicode characters be permitted, by default False

Returns

The sluggified string

Return type

str

Raises

AttributeError – The input must be a string

Examples

>>> slugify("Jack & Jill like numbers 1,2,3 and 4 and silly characters ?%.$!/")
'jack-jill-like-numbers-123-and-4-and-silly-characters'

References

1: Django. (n.d.). Django/text.py at main · Django/Django. GitHub. Retrieved January 2, 2023, from https://github.com/django/django/blob/main/django/utils/text.py

infoml.utils.downloadurl(url: str, file: str | Path = CONFIG.tempdir(), overwrite: bool = False, progress: bool = True) → pathlib.Path[source]

Download and save file from a given URL

Parameters

url (str) – The URL to download the file from
file (str, optional) – Path to file (or directory) where downloaded file will be stored, by default the file will be saved to a temporary directory
overwrite (bool, optional) – Should existing files be overwritten, by default False
progress (bool, optional) – Should a progress bar be displayed, by default True

Returns

Path to downloaded file

Return type

Path

Raises

FileNotFoundError – If the file does not exist
FileExistsError – If the file already exists and overwrite is False
ConnectionError – If the URL is not valid

Examples

>>> downloadurl("https://www.google.com/images/branding/googlelogo/2x/googlelogo_color_272x92dp.png")
PosixPath('/tmp/googlelogo_color_272x92dp.png')

class infoml.utils.SQLite(file: str | Path, quiet: bool = False, **kwargs)[source]

Wrapper for connecting to and querying SQLite databases

file

Path to SQLite database file

Type: Path

conn

Connection to SQLite database

Type: sqlite3.Connection

execute(query: str, \*args, \*\*kwargs) → sqlite3.Cursor[source]: Execute a query on the database

select(query: str, \*args, \*\*kwargs) → list[sqlite3.Row][source]: Execute a query on the database and return the results as a DataFrame

insert(table: str, data: dict, \*\*kwargs) → None[source]: Insert data into a table

is_table(table: str) → bool[source]: Check if a table exists in the database

drop(table: str) → None[source]: Drop a table from the database

tables() → dict[source]: Return a list of tables in the database and their schema

close() → None[source]: Close the connection to the database

__enter__()[source]: Enter context manager

__exit__(exc_type, exc_value, traceback)[source]: Exit context manager

__repr__() → str[source]: Return string representation of SQLite class

__str__() → str[source]: Return string representation of SQLite class

execute(query: str, *args, **kwargs) → sqlite3.Cursor | DataFrame | None[source]

Execute a query

Parameters: query (str) – Query to execute
Returns: Cursor object
Return type: sqlite3.Cursor
Raises: AttributeError – If the input is not a string

Examples

>>> db = SQLite("test.db")
>>> db.execute("CREATE TABLE IF NOT EXISTS test (id INTEGER PRIMARY KEY, name TEXT)")
<sqlite3.Cursor object at 0x7f8b8c0b0e00>
>>> db.execute("INSERT INTO test (name) VALUES ('John')")
<sqlite3.Cursor object at 0x7f8b8c0b0e00>
>>> db.execute("INSERT INTO test (name) VALUES ('Jane')")
<sqlite3.Cursor object at 0x7f8b8c0b0e00>
>>> db.close()

select(query: str, *args, **kwargs) → pandas.DataFrame[source]

Execute a SELECT query and return the results as a DataFrame

Parameters: query (str) – Query to execute
Returns: Results of query
Return type: DataFrame
Raises: AttributeError – If the input is not a string

Examples

>>> db = SQLite("test.db")
>>> db.select("SELECT * FROM test")
    id  name  age
    0  1  John   30
    1  2  Jane   25

insert(table: str, data: dict, **kwargs) → None[source]

Insert data into a table

Parameters

table (str) – Name of table
data (dict) – Data to insert

Raises

AttributeError – If the table does not exist If the dictionary values are not lists of the same length If a database column is missing from the dictionary

Examples

>>> db = SQLite("test.db")
>>> data = {'name': ['John', 'James', 'Rose', 'Jane'],
            'age':  [30, 25, 60, 45]}
>>> db.insert("test", data)
>>> db.close()

is_table(table: str) → bool[source]

Check if a table exists in the database

Parameters: table (str) – Name of table
Returns: True if table exists, False otherwise
Return type: bool

Examples

>>> db = SQLite("test.db")
>>> db.is_table("test")
True
>>> db.is_table("foo")
False

drop(table: str) → None[source]

Drop a table from the database

Parameters: table (str) – Name of table

Examples

>>> db = SQLite("test.db")
>>> db.drop("test")

tables() → dict[source]

List all tables in the database and their schema

Returns: Dictionary of table names and their schema
Return type: dict

Examples

>>> db = SQLite("test.db")
>>> db.tables()
{'test': 'CREATE TABLE test (id INTEGER PRIMARY KEY, name TEXT)'}

close() → None[source]: Close the database connection

infoml.utils.iohead(file: str, n: int = 5) → None[source]

Print the first n rows of a text file

Parameters

file (str) – Name of file
n (int, optional) – Number of rows to print

infoml.utils.system(command: str, stdout: str | None = None, stderr: str | None = None, quiet: bool = False, *args, **kwargs) → str[source]

Run a system command; allows you to redirect stdout and stderr.

Parameters

command (str) – Command to run
stdout (str, optional) – File to redirect stdout to, by default ‘’
stderr (str, optional) – File to redirect stderr to, by default ‘’
quiet (bool, optional) – Suppress output, by default False

Returns

Output from the command

Return type

str

infoml.utils

Module Contents

Classes

Functions

`infoml.utils`