Move command usage text to beginning

so its more stable, and not move around as the commands are improved over time.

Also removed spaces between use statements, so its sorted in a standard way by rustfmt.

Will also make it easier to parse out the usage text in the future.

README.md

@@ -28,51 +28,51 @@ See [FAQ](https://github.com/jqnatividad/qsv/discussions/categories/faq) for mor
 | Command | Description |
 | --- | --- |
 | [apply](/src/cmd/apply.rs#L29-L30)[^1][^5] | Apply series of string, date, currency & geocoding transformations to a CSV column. It also has some basic [NLP](https://en.wikipedia.org/wiki/Natural_language_processing) functions ([similarity](https://crates.io/crates/strsim), [sentiment analysis](https://crates.io/crates/vader_sentiment), [profanity](https://docs.rs/censor/latest/censor/), [eudex](https://github.com/ticki/eudex#eudex-a-blazingly-fast-phonetic-reductionhashing-algorithm) & [language detection](https://crates.io/crates/whatlang)). |
-| [behead](/src/cmd/behead.rs#L7) | Drop headers from a CSV. |
-| [cat](/src/cmd/cat.rs#L7) | Concatenate CSV files by row or by column. |
-| [count](/src/cmd/count.rs#L8)[^2] | Count the rows in a CSV file. (Instantaneous with an index.) |
-| [dedup](/src/cmd/dedup.rs#L14)[^3][^5] | Remove redundant rows (See also `sortcheck` command). |
-| [enum](/src/cmd/enumerate.rs#L10-L12) | Add a new column enumerating rows by adding a column of incremental or uuid identifiers. Can also be used to copy a column or fill a new column with a constant value. |
-| [excel](/src/cmd/excel.rs#L12) | Exports a specified Excel/ODS sheet to a CSV file. |
-| [exclude](/src/cmd/exclude.rs#L18)[^2] | Removes a set of CSV data from another set based on the specified columns. |
-| [explode](/src/cmd/explode.rs#L8-L9) | Explode rows into multiple ones by splitting a column value based on the given separator. |
-| [extsort](/src/cmd/extsort.rs#L13)[^5] | Sort an arbitrarily large CSV/text file using a multithreaded [external merge sort](https://en.wikipedia.org/wiki/External_sorting) algorithm. |
-| [fetch](/src/cmd/fetch.rs#L28) | Fetches data from web services for every row using **HTTP Get**. Comes with [jql](https://github.com/yamafaktory/jql#%EF%B8%8F-usage) JSON query language support, dynamic throttling ([RateLimit](https://tools.ietf.org/id/draft-polli-ratelimit-headers-00.html)) & caching with optional [Redis](https://redis.io/) support for persistent caching. |
-| [fetchpost](/src/cmd/fetchpost.rs#L28-L29) | Similar to `fetch`, but uses **HTTP Post**. ([HTTP GET vs POST methods](https://www.geeksforgeeks.org/difference-between-http-get-and-post-methods/)) |
-| [fill](/src/cmd/fill.rs#L13) | Fill empty values. |
-| [fixlengths](/src/cmd/fixlengths.rs#L9-L11) | Force a CSV to have same-length records by either padding or truncating them. |
-| [flatten](/src/cmd/flatten.rs#L12-L15) | A flattened view of CSV records. Useful for viewing one record at a time.<br />e.g. `qsv slice -i 5 data.csv \| qsv flatten`. |
-| [fmt](/src/cmd/fmt.rs#L7) | Reformat a CSV with different delimiters, record terminators or quoting rules. (Supports ASCII delimited data.) |
-| [foreach](/src/cmd/foreach.rs#L16-L17)[^1] | Loop over a CSV to execute bash commands. (not available on Windows) |
-| [frequency](/src/cmd/frequency.rs#L15)[^2][^4] | Build [frequency tables](https://statisticsbyjim.com/basics/frequency-table/) of each column. (Uses multithreading to go faster if an index is present.) |
-| [generate](/src/cmd/generate.rs#L12-L13)[^1] | Generate test data by profiling a CSV using [Markov decision process](https://crates.io/crates/test-data-generation) machine learning. |
-| [headers](/src/cmd/headers.rs#L11) | Show the headers of a CSV. Or show the intersection of all headers between many CSV files. |
-| [index](/src/cmd/index.rs#L13-L14) | Create an index for a CSV. This is very quick & provides constant time indexing into the CSV file. Also enables multithreading for `frequency`, `split`, `stats` and `schema` commands. |
-| [input](/src/cmd/input.rs#L8)[^2] | Read CSV data with special quoting, trimming, line-skipping and UTF-8 transcoding rules. Typically used to "normalize" a CSV for further processing with other qsv commands. |
-| [join](/src/cmd/join.rs#L18)[^2] | Inner, outer, cross, anti & semi joins. Uses a simple hash index to make it fast. |
-| [jsonl](/src/cmd/jsonl.rs#L11) | Convert newline-delimited JSON ([JSONL](https://jsonlines.org/)/[NDJSON](http:https://ndjson.org/)) to CSV. See `tojsonl` command to convert CSV to JSONL.
-| [lua](/src/cmd/lua.rs#L12-L13)[^1] | Execute a [Lua](https://www.lua.org/about.html) 5.4.4 script over CSV lines to transform, aggregate or filter them. |
-| [partition](/src/cmd/partition.rs#L17) | Partition a CSV based on a column value. |
-| [pseudo](/src/cmd/pseudo.rs#L10-L11) | [Pseudonymise](https://en.wikipedia.org/wiki/Pseudonymization) the value of the given column by replacing them with an incremental identifier. |
-| [py](/src/cmd/python.rs#L45-L46)[^1] | Evaluate a Python expression over CSV lines to transform, aggregate or filter them. Python's [f-strings](https://www.freecodecamp.org/news/python-f-strings-tutorial-how-to-use-f-strings-for-string-formatting/) is particularly useful for extended formatting (Python 3.8+ required). |
-| [rename](/src/cmd/rename.rs#L7) | Rename the columns of a CSV efficiently. |
-| [replace](/src/cmd/replace.rs#L14) | Replace CSV data using a regex. |
-| [reverse](/src/cmd/reverse.rs#L7)[^3] | Reverse order of rows in a CSV. Unlike the `sort --reverse` command, it preserves the order of rows with the same key. |
-| [sample](/src/cmd/sample.rs#L13-L14)[^2] | Randomly draw rows (with optional seed) from a CSV using [reservoir sampling](https://en.wikipedia.org/wiki/Reservoir_sampling) (i.e., use memory proportional to the size of the sample). |
-| [schema](/src/cmd/schema.rs#L24)[^4] | Infer schema from CSV data and output in [JSON Schema](https://json-schema.org/) format. Uses multithreading to go faster if an index is present. See `validate` command to use the generated JSON Schema to validate if similar CSVs comply with the schema. |
-| [search](/src/cmd/search.rs#L15) | Run a regex over a CSV. Applies the regex to each field individually & shows only matching rows. |
-| [searchset](/src/cmd/searchset.rs#L19) | **Run multiple regexes over a CSV in a single pass.** Applies the regexes to each field individually & shows only matching rows. |
-| [select](/src/cmd/select.rs#L8) | Select, re-order, duplicate or drop columns. |
-| [slice](/src/cmd/slice.rs#L10-L11)[^2][^3] | Slice rows from any part of a CSV. When an index is present, this only has to parse the rows in the slice (instead of all rows leading up to the start of the slice). |
-| [sniff](/src/cmd/sniff.rs#L10-L11)[^2] | Quickly sniff CSV metadata (delimiter, header row, preamble rows, quote character, flexible, is_utf8, number of records, number of fields, field names & data types). |
-| [sort](/src/cmd/sort.rs#L13)[^5] | Sorts CSV data in alphabetical, numerical, reverse or random (with optional seed) order (See also `extsort` & `sortcheck` commands). |
-| [sortcheck](/src/cmd/sortcheck.rs#L17-L18)[^2] | Check if a CSV is sorted. With the --json options, also retrieve record count, sort breaks & duplicate count. |
-| [split](/src/cmd/split.rs#L14)[^2][^4] | Split one CSV file into many CSV files of N chunks. (Uses multithreading to go faster if an index is present.) |
-| [stats](/src/cmd/stats.rs#L26)[^2][^3][^4] | Infer data type (Null, String, Float, Integer, Date, DateTime) & compute descriptive statistics for each column in a CSV (sum, min/max, min/max length, mean, stddev, variance, nullcount, quartiles, IQR, lower/upper fences, skewness, median, mode & cardinality). Uses multithreading to go faster if an index is present. |
-| [table](/src/cmd/table.rs#L12)[^3] | Show aligned output of a CSV using [elastic tabstops](https://github.com/BurntSushi/tabwriter). |
-| [tojsonl](/src/cmd/tojsonl.rs#L14)[^4] | Converts CSV to a newline-delimited JSON (JSONL/NDJSON). See `jsonl` command to convert JSONL to CSV. |
-| [transpose](/src/cmd/transpose.rs#L9)[^3] | Transpose rows/columns of a CSV. |
-| [validate](/src/cmd/validate.rs#L30-L31)[^2][^5] | Validate CSV data with a JSON Schema (See `schema` command). If no jsonschema file is provided, validates if a CSV conforms to the [RFC 4180 standard](https://datatracker.ietf.org/doc/html/rfc4180). |
+| [behead](/src/cmd/behead.rs#L2) | Drop headers from a CSV. |
+| [cat](/src/cmd/cat.rs#L2) | Concatenate CSV files by row or by column. |
+| [count](/src/cmd/count.rs#L2)[^2] | Count the rows in a CSV file. (Instantaneous with an index.) |
+| [dedup](/src/cmd/dedup.rs#L2)[^3][^5] | Remove redundant rows (See also `sortcheck` command). |
+| [enum](/src/cmd/enumerate.rs#L2-L3) | Add a new column enumerating rows by adding a column of incremental or uuid identifiers. Can also be used to copy a column or fill a new column with a constant value. |
+| [excel](/src/cmd/excel.rs#L2) | Exports a specified Excel/ODS sheet to a CSV file. |
+| [exclude](/src/cmd/exclude.rs#L2)[^2] | Removes a set of CSV data from another set based on the specified columns. |
+| [explode](/src/cmd/explode.rs#L2-L3) | Explode rows into multiple ones by splitting a column value based on the given separator. |
+| [extsort](/src/cmd/extsort.rs#L2)[^5] | Sort an arbitrarily large CSV/text file using a multithreaded [external merge sort](https://en.wikipedia.org/wiki/External_sorting) algorithm. |
+| [fetch](/src/cmd/fetch.rs#L2) | Fetches data from web services for every row using **HTTP Get**. Comes with [jql](https://github.com/yamafaktory/jql#%EF%B8%8F-usage) JSON query language support, dynamic throttling ([RateLimit](https://tools.ietf.org/id/draft-polli-ratelimit-headers-00.html)) & caching with optional [Redis](https://redis.io/) support for persistent caching. |
+| [fetchpost](/src/cmd/fetchpost.rs#L2-L3) | Similar to `fetch`, but uses **HTTP Post**. ([HTTP GET vs POST methods](https://www.geeksforgeeks.org/difference-between-http-get-and-post-methods/)) |
+| [fill](/src/cmd/fill.rs#L2) | Fill empty values. |
+| [fixlengths](/src/cmd/fixlengths.rs#L2-L4) | Force a CSV to have same-length records by either padding or truncating them. |
+| [flatten](/src/cmd/flatten.rs#L2-L5) | A flattened view of CSV records. Useful for viewing one record at a time.<br />e.g. `qsv slice -i 5 data.csv \| qsv flatten`. |
+| [fmt](/src/cmd/fmt.rs#L2) | Reformat a CSV with different delimiters, record terminators or quoting rules. (Supports ASCII delimited data.) |
+| [foreach](/src/cmd/foreach.rs#L3-L4)[^1] | Loop over a CSV to execute bash commands. (not available on Windows) |
+| [frequency](/src/cmd/frequency.rs#L2)[^2][^4] | Build [frequency tables](https://statisticsbyjim.com/basics/frequency-table/) of each column. (Uses multithreading to go faster if an index is present.) |
+| [generate](/src/cmd/generate.rs#L2-L3)[^1] | Generate test data by profiling a CSV using [Markov decision process](https://crates.io/crates/test-data-generation) machine learning. |
+| [headers](/src/cmd/headers.rs#L2) | Show the headers of a CSV. Or show the intersection of all headers between many CSV files. |
+| [index](/src/cmd/index.rs#L2-L3) | Create an index for a CSV. This is very quick & provides constant time indexing into the CSV file. Also enables multithreading for `frequency`, `split`, `stats` and `schema` commands. |
+| [input](/src/cmd/input.rs#L2)[^2] | Read CSV data with special quoting, trimming, line-skipping and UTF-8 transcoding rules. Typically used to "normalize" a CSV for further processing with other qsv commands. |
+| [join](/src/cmd/join.rs#L2)[^2] | Inner, outer, cross, anti & semi joins. Uses a simple hash index to make it fast. |
+| [jsonl](/src/cmd/jsonl.rs#L2) | Convert newline-delimited JSON ([JSONL](https://jsonlines.org/)/[NDJSON](http:https://ndjson.org/)) to CSV. See `tojsonl` command to convert CSV to JSONL.
+| [lua](/src/cmd/lua.rs#L2-L3)[^1] | Execute a [Lua](https://www.lua.org/about.html) 5.4.4 script over CSV lines to transform, aggregate or filter them. |
+| [partition](/src/cmd/partition.rs#L2) | Partition a CSV based on a column value. |
+| [pseudo](/src/cmd/pseudo.rs#L2-L3) | [Pseudonymise](https://en.wikipedia.org/wiki/Pseudonymization) the value of the given column by replacing them with an incremental identifier. |
+| [py](/src/cmd/python.rs#L2-L3)[^1] | Evaluate a Python expression over CSV lines to transform, aggregate or filter them. Python's [f-strings](https://www.freecodecamp.org/news/python-f-strings-tutorial-how-to-use-f-strings-for-string-formatting/) is particularly useful for extended formatting (Python 3.8+ required). |
+| [rename](/src/cmd/rename.rs#L2) | Rename the columns of a CSV efficiently. |
+| [replace](/src/cmd/replace.rs#L2) | Replace CSV data using a regex. |
+| [reverse](/src/cmd/reverse.rs#L2)[^3] | Reverse order of rows in a CSV. Unlike the `sort --reverse` command, it preserves the order of rows with the same key. |
+| [sample](/src/cmd/sample.rs#L2-L3)[^2] | Randomly draw rows (with optional seed) from a CSV using [reservoir sampling](https://en.wikipedia.org/wiki/Reservoir_sampling) (i.e., use memory proportional to the size of the sample). |
+| [schema](/src/cmd/schema.rs#L2)[^4] | Infer schema from CSV data and output in [JSON Schema](https://json-schema.org/) format. Uses multithreading to go faster if an index is present. See `validate` command to use the generated JSON Schema to validate if similar CSVs comply with the schema. |
+| [search](/src/cmd/search.rs#L2) | Run a regex over a CSV. Applies the regex to each field individually & shows only matching rows. |
+| [searchset](/src/cmd/searchset.rs#L2) | **Run multiple regexes over a CSV in a single pass.** Applies the regexes to each field individually & shows only matching rows. |
+| [select](/src/cmd/select.rs#L2) | Select, re-order, duplicate or drop columns. |
+| [slice](/src/cmd/slice.rs#L2-L3)[^2][^3] | Slice rows from any part of a CSV. When an index is present, this only has to parse the rows in the slice (instead of all rows leading up to the start of the slice). |
+| [sniff](/src/cmd/sniff.rs#L2-L3)[^2] | Quickly sniff CSV metadata (delimiter, header row, preamble rows, quote character, flexible, is_utf8, number of records, number of fields, field names & data types). |
+| [sort](/src/cmd/sort.rs#L2)[^5] | Sorts CSV data in alphabetical, numerical, reverse or random (with optional seed) order (See also `extsort` & `sortcheck` commands). |
+| [sortcheck](/src/cmd/sortcheck.rs#L2-L3)[^2] | Check if a CSV is sorted. With the --json options, also retrieve record count, sort breaks & duplicate count. |
+| [split](/src/cmd/split.rs#L2)[^2][^4] | Split one CSV file into many CSV files of N chunks. (Uses multithreading to go faster if an index is present.) |
+| [stats](/src/cmd/stats.rs#L2)[^2][^3][^4] | Infer data type (Null, String, Float, Integer, Date, DateTime) & compute descriptive statistics for each column in a CSV (sum, min/max, min/max length, mean, stddev, variance, nullcount, quartiles, IQR, lower/upper fences, skewness, median, mode & cardinality). Uses multithreading to go faster if an index is present. |
+| [table](/src/cmd/table.rs#L2)[^3] | Show aligned output of a CSV using [elastic tabstops](https://github.com/BurntSushi/tabwriter). |
+| [tojsonl](/src/cmd/tojsonl.rs#L2)[^4] | Converts CSV to a newline-delimited JSON (JSONL/NDJSON). See `jsonl` command to convert JSONL to CSV. |
+| [transpose](/src/cmd/transpose.rs#L2)[^3] | Transpose rows/columns of a CSV. |
+| [validate](/src/cmd/validate.rs#L2-L3)[^2][^5] | Validate CSV data with a JSON Schema (See `schema` command). If no jsonschema file is provided, validates if a CSV conforms to the [RFC 4180 standard](https://datatracker.ietf.org/doc/html/rfc4180). |
 
 [^1]: enabled by optional feature flag. Not available on `qsvlite` & `qsvdp`.
 [^2]: uses an index when available. 

src/cmd/behead.rs

@@ -1,8 +1,3 @@
-use crate::config::{Config, Delimiter};
-use crate::util;
-use crate::CliResult;
-use serde::Deserialize;
-
 static USAGE: &str = "
 Drop a CSV file's header.
 
@@ -16,6 +11,11 @@ Common options:
  Must be a single character. (default: ,)
 ";
 
+use crate::config::{Config, Delimiter};
+use crate::util;
+use crate::CliResult;
+use serde::Deserialize;
+
 #[derive(Deserialize)]
 struct Args {
  arg_input: Option<String>,

src/cmd/cat.rs

@@ -1,8 +1,3 @@
-use crate::config::{Config, Delimiter};
-use crate::util;
-use crate::CliResult;
-use serde::Deserialize;
-
 static USAGE: &str = "
 Concatenates CSV data by column or by row.
 
@@ -37,6 +32,11 @@ Common options:
  Must be a single character. (default: ,)
 ";
 
+use crate::config::{Config, Delimiter};
+use crate::util;
+use crate::CliResult;
+use serde::Deserialize;
+
 #[derive(Deserialize)]
 struct Args {
  cmd_rows: bool,

src/cmd/count.rs

@@ -1,9 +1,3 @@
-use crate::config::{Config, Delimiter};
-use crate::util;
-use crate::CliResult;
-use log::{debug, info};
-use serde::Deserialize;
-
 static USAGE: &str = "
 Prints a count of the number of records in the CSV data.
 
@@ -24,6 +18,12 @@ Common options:
  Must be a single character. (default: ,)
 ";
 
+use crate::config::{Config, Delimiter};
+use crate::util;
+use crate::CliResult;
+use log::{debug, info};
+use serde::Deserialize;
+
 #[derive(Deserialize)]
 struct Args {
  arg_input: Option<String>,

src/cmd/dedup.rs

@@ -1,15 +1,3 @@
-use std::cmp;
-
-use crate::config::{Config, Delimiter};
-use crate::select::SelectColumns;
-use crate::util;
-use crate::CliResult;
-use csv::ByteRecord;
-use rayon::prelude::*;
-use serde::Deserialize;
-
-use crate::cmd::sort::iter_cmp;
-
 static USAGE: &str = r#"
 Deduplicates CSV rows. 
 
@@ -56,6 +44,16 @@ Common options:
  Must be a single character. (default: ,)
 "#;
 
+use crate::config::{Config, Delimiter};
+use crate::select::SelectColumns;
+use crate::util;
+use crate::CliResult;
+use csv::ByteRecord;
+use rayon::prelude::*;
+use serde::Deserialize;
+use std::cmp;
+
+use crate::cmd::sort::iter_cmp;
 #[derive(Deserialize)]
 struct Args {
  arg_input: Option<String>,

src/cmd/enumerate.rs

@@ -1,11 +1,3 @@
-use uuid::Uuid;
-
-use crate::config::{Config, Delimiter};
-use crate::select::SelectColumns;
-use crate::util;
-use crate::CliResult;
-use serde::Deserialize;
-
 static USAGE: &str = r#"
 Add a new column enumerating the lines of a CSV file. This can be useful to keep
 track of a specific line order, give a unique identifier to each line or even
@@ -54,6 +46,13 @@ Common options:
  Must be a single character. (default: ,)
 "#;
 
+use crate::config::{Config, Delimiter};
+use crate::select::SelectColumns;
+use crate::util;
+use crate::CliResult;
+use serde::Deserialize;
+use uuid::Uuid;
+
 const NULL_VALUE: &str = "<NULL>";
 
 #[derive(Deserialize)]

src/cmd/excel.rs

@@ -1,13 +1,3 @@
-use crate::config::Config;
-use crate::util;
-use crate::CliResult;
-use calamine::{open_workbook_auto, DataType, Range, Reader};
-use log::{debug, info};
-use serde::Deserialize;
-use std::cmp;
-use std::path::PathBuf;
-use thousands::Separable;
-
 static USAGE: &str = r#"
 Exports a specified Excel/ODS sheet to a CSV file.
 
@@ -65,6 +55,16 @@ Common options:
  -o, --output <file> Write output to <file> instead of stdout.
 "#;
 
+use crate::config::Config;
+use crate::util;
+use crate::CliResult;
+use calamine::{open_workbook_auto, DataType, Range, Reader};
+use log::{debug, info};
+use serde::Deserialize;
+use std::cmp;
+use std::path::PathBuf;
+use thousands::Separable;
+
 #[derive(Deserialize)]
 struct Args {
  arg_input: String,

src/cmd/exclude.rs

@@ -1,19 +1,3 @@
-use ahash::AHashMap;
-use std::collections::hash_map::Entry;
-use std::fmt;
-use std::fs;
-use std::io;
-use std::str;
-
-use byteorder::{BigEndian, WriteBytesExt};
-
-use crate::config::{Config, Delimiter};
-use crate::index::Indexed;
-use crate::select::{SelectColumns, Selection};
-use crate::util;
-use crate::CliResult;
-use serde::Deserialize;
-
 static USAGE: &str = "
 Removes a set of CSV data from another set based on the specified columns.
 
@@ -48,6 +32,20 @@ Common options:
  Must be a single character. (default: ,)
 ";
 
+use crate::config::{Config, Delimiter};
+use crate::index::Indexed;
+use crate::select::{SelectColumns, Selection};
+use crate::util;
+use crate::CliResult;
+use ahash::AHashMap;
+use byteorder::{BigEndian, WriteBytesExt};
+use serde::Deserialize;
+use std::collections::hash_map::Entry;
+use std::fmt;
+use std::fs;
+use std::io;
+use std::str;
+
 type ByteString = Vec<u8>;
 
 #[derive(Deserialize)]