> For the complete documentation index, see [llms.txt](https://docs.borndigital.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.borndigital.ai/for-advanced-users/conversation-design-tips/string-slicing.md).

# String slicing

Let's delve into the concept of string slicing and how it can be applied to extract meaningful pieces of information to be used in conversational design.

## Example use case

Consider an order ID composed of 12 digits, structured as follows:

* The first 4 digits represent the year of creation.
* The last digit denotes the type of buyer, where '4' indicates a purchase by an individual and '5' denotes a purchase by a company.
* The fifth and sixth digits represent the product category, with specific numerical codes assigned to different product types. For instance, '10' might represent a refrigerator, '25' a washing machine, '06' a computer, and so forth.

<figure><img src="/files/ZP33drA57V66P3DAuQBn" alt=""><figcaption></figcaption></figure>

Let's take the following order ID as an example. From user's utterance we have extracted an order id and **saved it as a string** to a variable named order\_id.

<figure><img src="/files/0Y662SzbJIRMVzYTPBf4" alt=""><figcaption></figcaption></figure>

Now, let's break down this order ID into its constituent parts using string slicing:

**General rules:**

1. **Slicing from the start:**
   * When slicing from the start of the string, you specify the starting index as `0`.
   * Example: `string_variable[start:]`
   * This will slice the string starting from the specified index `start` until the end of the string.
2. **Slicing from the end:**
   * When slicing from the end of the string, you can use negative indices to specify positions relative to the end of the string.
   * Example: `string_variable[-end:]`
   * This will slice the string starting from `end` positions from the end of the string until the end of the string.
3. **Slicing in an interval:**
   * You can also specify an interval (step) between characters to be included in the slice.
   * Example: `string_variable[start:end:interval]`
   * The interval specifies how many characters to skip after each character is included in the slice.
   * Omitting `start` and `end` (or both) will default to the start and end of the string, respectively.
   * Omitting `interval` will default to `1`, meaning consecutive characters will be included.
   * If `interval` is negative, the slice will be performed in reverse order.

\
Let's break it down for order\_id = "202406987614" and save each substring to a separate variable:

**Extracting the year**

* The first 4 digits in order\_id represent the year, so we have to slice the string after **4** characters from the **start** of the string.
* <mark style="color:red;">**2024**</mark>06987614
* Store value "2024" in a variable named `order_year`.

{% code title="order\_year" %}

```
order_id[:4] 
```

{% endcode %}

<figure><img src="/files/n3AgL3kJFhlRZJTlwZcb" alt=""><figcaption></figcaption></figure>

**Identifying the product category**

* The product category is coded as the **fifth and sixth** digits in the string, so we have to slice out all characters between the fifth (included) and the seventh (excluded).
* 2024<mark style="color:purple;">**06**</mark>987614
* Store value "06" in a variable `product_category`.

{% code title="product\_category" %}

```
order_id[5:7]
```

{% endcode %}

<figure><img src="/files/mjlPfiz04hRFnpDHL5Fm" alt=""><figcaption></figcaption></figure>

**Determining the buyer type**

* The last digit in a string represents buyer type, so we have to slice **1 character from the end** of a string.
* 20240698761<mark style="color:green;">**4**</mark>
* Store value "4" in a variable named `buyer_type.`

{% code title="buyer\_type" %}

```
order_id[-1]
```

{% endcode %}

<figure><img src="/files/gTAuFAndAfYe6KUXGAvY" alt=""><figcaption></figcaption></figure>

***

## Other use cases and ideas

Here are additional use cases for utilizing string slicing in chatbots and voicebots:

1. **Extracting Date and Time from ISO Format:**
   * You can use string slicing to extract different parts of the date and time from the YYYY-MM-DD-T-HH:mm.SS format.
   * For example, if you need only the date, you can use `string_variable[:10]` to slice the first 10 characters.
   * To extract the time, you can use `string_variable[11:19]` to slice the time segment.

2. **Extracting Area Code from Phone Numbers:**
   * If you have phone numbers in a format with an area code, you can use string slicing to extract this area code.
   * For instance, if the area code always consists of a certain number of digits (e.g., 3), you can use `string_variable[:3]` to slice the first three digits.

3. **Extracting Last 4 Digits from Social Security Numbers:**

   * If you need to extract a specific part from a social security number, such as the last 4 digits, you can use string slicing.
   * By using a negative index, you can easily obtain the last part of the string, for example, `string_variable[-4:]` to extract the last 4 characters.

4. **Extracting Information from Personal Identification Numbers (PINs) or Social Security Numbers (SSNs):**
   * Personal identification numbers, such as social security numbers, often encode information like date of birth and gender. String slicing can be used to extract this information.
   * For example, in some systems, the first few digits of a social security number might encode the individual's birthdate and gender.
   * By defining specific slicing patterns, you can extract the relevant portions of the SSN to obtain the date of birth and gender information.
   * For instance, you might use `string_variable[:6]` to extract the first six digits representing the birthdate, and then further processing can decode these digits to derive the actual date of birth and gender.