Move import down to the chrono example

docs/src/rust/getting-started/series-dataframes.rs

@@ -1,54 +1,57 @@
-
-fn main() -> Result<(), Box<dyn std::error::Error>>{
+fn main() -> Result<(), Box<dyn std::error::Error>> {
     // --8<-- [start:series]
     use polars::prelude::*;
-    use chrono::prelude::*; // This will be needed for the exercise below:
 
     let s = Series::new("a", [1, 2, 3, 4, 5]);
     println!("{}", s);
     // --8<-- [end:series]
-    
+
     // --8<-- [start:minmax]
     let s = Series::new("a", [1, 2, 3, 4, 5]);
     // The use of generics is necessary for the type system
     println!("{}", s.min::<u64>().unwrap());
     println!("{}", s.max::<u64>().unwrap());
     // --8<-- [end:minmax]
-    
+
     // --8<-- [start:string]
     // This operation is not directly available on the Series object yet, only on the DataFrame
     // --8<-- [end:string]
-    
+
     // --8<-- [start:dt]
     // This operation is not directly available on the Series object yet, only on the DataFrame
     // --8<-- [end:dt]
-    
+
     // --8<-- [start:dataframe]
-    let df: DataFrame = df!("integer" => &[1, 2, 3, 4, 5],
-                            "date" => &[
-                                        NaiveDate::from_ymd_opt(2022, 1, 1).unwrap().and_hms_opt(0, 0, 0).unwrap(),
-                                        NaiveDate::from_ymd_opt(2022, 1, 2).unwrap().and_hms_opt(0, 0, 0).unwrap(),
-                                        NaiveDate::from_ymd_opt(2022, 1, 3).unwrap().and_hms_opt(0, 0, 0).unwrap(),
-                                        NaiveDate::from_ymd_opt(2022, 1, 4).unwrap().and_hms_opt(0, 0, 0).unwrap(),
-                                        NaiveDate::from_ymd_opt(2022, 1, 5).unwrap().and_hms_opt(0, 0, 0).unwrap()
-                            ],
-                            "float" => &[4.0, 5.0, 6.0, 7.0, 8.0]
-                            ).expect("should not fail");
+    use chrono::prelude::*;
+
+    let df: DataFrame = df!(
+        "integer" => &[1, 2, 3, 4, 5],
+        "date" => &[
+            NaiveDate::from_ymd_opt(2022, 1, 1).unwrap().and_hms_opt(0, 0, 0).unwrap(),
+            NaiveDate::from_ymd_opt(2022, 1, 2).unwrap().and_hms_opt(0, 0, 0).unwrap(),
+            NaiveDate::from_ymd_opt(2022, 1, 3).unwrap().and_hms_opt(0, 0, 0).unwrap(),
+            NaiveDate::from_ymd_opt(2022, 1, 4).unwrap().and_hms_opt(0, 0, 0).unwrap(),
+            NaiveDate::from_ymd_opt(2022, 1, 5).unwrap().and_hms_opt(0, 0, 0).unwrap()
+        ],
+        "float" => &[4.0, 5.0, 6.0, 7.0, 8.0],
+    )
+    .unwrap();
+
     println!("{}", df);
     // --8<-- [end:dataframe]
-    
+
     // --8<-- [start:head]
     println!("{}", df.head(Some(3)));
     // --8<-- [end:head]
-    
+
     // --8<-- [start:tail]
     println!("{}", df.tail(Some(3)));
     // --8<-- [end:tail]
-    
+
     // --8<-- [start:sample]
     println!("{}", df.sample_n(2, false, true, None)?);
     // --8<-- [end:sample]
-    
+
     // --8<-- [start:describe]
     println!("{:?}", df.describe(None));
     // --8<-- [end:describe]