Remove scientific notation when converting floats to strings.

[alexhallam]

Which part is this question about
parquet

Describe your question
I would like to get a string of the values, but not in scientific notation (if 0.01 then return "0.01" not "1E-2").

Additional context

I am trying to read parquets and print the output, but the fact that conversion to string results in a scientific notation is making the task harder for me. I am guessing there is a simple way to make sure I get the full value without conversion to scientific notation, but I have not found a method for that yet.

I have a snippet of code below showing the general idea.

[alamb]

Instead of calling c.1.to_string() perhaps you could use something like this (untested):

match c.1 {
  Field::Float(f) => format!("{}", f), // or however else you wanted to format floats 
  Feld::Double(f) => format!("{}", f), // or however else you wanted to format floats 
  _ => c.1.to_string()
}

[alexhallam]

Thanks. I will give this a try.

[alexhallam]

I am getting an error with the code below

    fn pull_rows(row: &parquet::record::Row) -> Vec<std::string::String> {
        row.get_column_iter()
            .map(|c: (&String, &Field)| match c.1 {
                Field::Float(f) => format!("{}", f),
                Field::Double(f) => format!("{}", f),
                _ => c.1.to_string(),
            })
            .collect::<Vec<_>>()
    }

here is the error

error[E0599]: no associated item named `Float` found for struct `arrow::datatypes::Field` in the current scope
   --> src/main.rs:292:24
    |
292 |                 Field::Float(f) => format!("{}", f), // or however else you wanted to format floats
    |                        ^^^^^ associated item not found in `arrow::datatypes::Field`

error[E0599]: no associated item named `Double` found for struct `arrow::datatypes::Field` in the current scope
   --> src/main.rs:293:24
    |
293 |                 Field::Double(f) => format!("{}", f), // or however else you wanted to format floats
    |                        ^^^^^^ associated item not found in `arrow::datatypes::Field`

Since Field::Float does not exist I am guessing I will need to do something like a f.data_type as shown here https://docs.rs/arrow/3.0.0/arrow/datatypes/struct.Field.html

[alamb]

@alexhallam I think the issue is that you are using the "wrong" Field -- the error message is for one.in Arrow and the one you probably need to use is in parquet: https://docs.rs/parquet/8.0.0/parquet/record/enum.Field.html

[alexhallam]

That fixed the issue. Thanks

[alamb]

Glad you figured out the problem.