From 2503956e832e81041b32b7ab5f6f3a2177c77f00 Mon Sep 17 00:00:00 2001
From: Ondrej Zeman <ozeman77@gmail.com>
Date: Mon, 16 Dec 2024 14:33:26 +0100
Subject: [PATCH] docs(python): Fix substr function param definition (#19054)

---
 crates/polars-sql/src/functions.rs                       | 2 +-
 py-polars/docs/source/reference/sql/functions/string.rst | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/crates/polars-sql/src/functions.rs b/crates/polars-sql/src/functions.rs
index ff1a926f27e3..988ef74692e2 100644
--- a/crates/polars-sql/src/functions.rs
+++ b/crates/polars-sql/src/functions.rs
@@ -424,7 +424,7 @@ pub(crate) enum PolarsSQLFunctions {
     /// ```
     StrPos,
     /// SQL 'substr' function
-    /// Returns a portion of the data (first character = 0) in the range.
+    /// Returns a portion of the data (first character = 1) in the range.
     ///   \[start, start + length]
     /// ```sql
     /// SELECT SUBSTR(column_1, 3, 5) FROM df;
diff --git a/py-polars/docs/source/reference/sql/functions/string.rst b/py-polars/docs/source/reference/sql/functions/string.rst
index 02ca13fd740b..555e696f8dc6 100644
--- a/py-polars/docs/source/reference/sql/functions/string.rst
+++ b/py-polars/docs/source/reference/sql/functions/string.rst
@@ -45,8 +45,8 @@ String
      - Returns the index of the given substring in the target string.
    * - :ref:`STRPTIME <strptime>`
      - Converts a string to a Datetime using a strftime-compatible formatting string.
-   * - :ref:`SUBSTRING <substring>`
-     - Returns a portion of the data (first character = 0) in the range [start, start + length].
+   * - :ref:`SUBSTR <substr>`
+     - Returns a portion of the data (first character = 1) in the range [start, start + length].
    * - :ref:`TIMESTAMP <timestamp>`
      - Converts a formatted timestamp/datetime string to an actual Datetime value.
    * - :ref:`UPPER <upper>`
@@ -617,9 +617,9 @@ Converts a string to a Datetime using a `chrono strftime <https://docs.rs/chrono
     # │ 2077 Feb 28 ┆ 10.45.00 ┆ 2077-02-28 10:45:00 │
     # └─────────────┴──────────┴─────────────────────┘
 
-.. _substring:
+.. _substr:
 
-SUBSTRING
+SUBSTR
 ---------
 Returns a slice of the string data (1-indexed) in the range [start, start + length].