String
The string module contains useful methods when it comes to manipulating and dealing with strings. Let's take a dive into their individual implementation.
Is String Object¶
The purpose of the is_string_object() method is to check whether a provided object is actually a string object, the method takes an obj as input, which is the object that will be used for checking.
Let's see how this translates to code:
In the example above we are able to verify that the object passed is actually a string. Let's take a look at another scenario below, this time with a different object type:
Convert to String¶
This method is used in order to convert a value to a string. It takes a value as an argument and converts it to a string.
Let's take a look into a couple examples below:
from everysk.core.string import to_string
to_string(123)
'123'
to_string({'key': 'value'})
"{'key': 'value'}"
to_string([1,2,3])
'[1, 2, 3]'
Normalize String¶
To better understand the importance of this method let's start with an example:
When we print the values defined above we get the following:
They may look the same but watch when we try to compare both values:
In the first variable the character is represented using only one unicode point U+0101, in the second variable the character is represented as two separate unicode points U+0061 (letter 'a') and U+0304 (the macron symbol)
Imagine that you have both characters I (U+2160) which is the roman numeral one and (U+0049) which is the latin capital letter I. In the surface they may look the same, but in fact they are different characters. This might be a problem when trying to compare two characters.
The normalize_string() method solves this problem by applying a unicode normalization based on their equivalence. Let's circle back to our example and see the full implementation
from everysk.core.string import normalize_string
aa = b'\xc4\x81'.decode('utf-8')
bb = b'a\xcc\x84'.decode('utf-8')
aa
'ā'
bb
'ā'
aa == bb
False
new_aa = normalize_string(aa)
new_bb = normalize_string(bb)
new_aa == new_bb
True
Normalize String For Search¶
This method implements the functionality of the previous normalize_string() method and goes even further by removing whitespaces and formatting the string to lowercase.
Let's take a look at the implementation below:
from everysk.core.string import normalize_string_to_search
normalize_string_to_search(' My Query ')
'my query'
Import From String¶
The import_from_string() method takes a dotted_path as argument, which refers to the dotted path of the python class or module, and returns the imported class according to the path provided.
This method uses the import_module() method from the importlib library to perform the import based on the string path provided as mentioned.
Below we have an implementation example:
from everysk.core.string import import_from_string
import_from_string('my_module.module_name.ClassName')
my_module.module_name.ClassName
In the cases when the provided dotted path is not valid or for some unknown reason the module cannot be imported, the method throws in a ModuleNotFoundError.