html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,issue,performed_via_github_app
https://github.com/simonw/sqlite-utils/issues/230#issuecomment-778812684,https://api.github.com/repos/simonw/sqlite-utils/issues/230,778812684,MDEyOklzc3VlQ29tbWVudDc3ODgxMjY4NA==,9599,2021-02-14T17:45:16Z,2021-02-14T17:45:16Z,OWNER,"Running this could take any CSV (or TSV) file and automatically detect the delimiter. If no header row is detected it could add `unknown1,unknown2` headers:

    sqlite-utils insert db.db data file.csv --sniff

(Using `--sniff` would imply `--csv`)

This could be called `--sniffer` instead but I like `--sniff` better.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",808008305,
https://github.com/simonw/sqlite-utils/issues/230#issuecomment-778815740,https://api.github.com/repos/simonw/sqlite-utils/issues/230,778815740,MDEyOklzc3VlQ29tbWVudDc3ODgxNTc0MA==,9599,2021-02-14T18:05:03Z,2021-02-14T18:05:03Z,OWNER,"The challenge here is how to read the first 2048 bytes and then reset the incoming file.

The Python docs example looks like this:

```python
with open('example.csv', newline='') as csvfile:
    dialect = csv.Sniffer().sniff(csvfile.read(1024))
    csvfile.seek(0)
    reader = csv.reader(csvfile, dialect)
```
Here's the relevant code in `sqlite-utils`: https://github.com/simonw/sqlite-utils/blob/726219c3503e77440975cd15b74d006639feb0f8/sqlite_utils/cli.py#L671-L679

The challenge is going to be having the `--sniff` option work with the progress bar. Here's how `file_progress()` works: https://github.com/simonw/sqlite-utils/blob/726219c3503e77440975cd15b74d006639feb0f8/sqlite_utils/utils.py#L106-L113

If `file.raw` is `stdin` can I do the equivalent of `csvfile.seek(0)` on it?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",808008305,
https://github.com/simonw/sqlite-utils/issues/230#issuecomment-778816333,https://api.github.com/repos/simonw/sqlite-utils/issues/230,778816333,MDEyOklzc3VlQ29tbWVudDc3ODgxNjMzMw==,9599,2021-02-14T18:08:44Z,2021-02-14T18:08:44Z,OWNER,"No, you can't `.seek(0)` on stdin:
```
  File ""/Users/simon/Dropbox/Development/sqlite-utils/sqlite_utils/cli.py"", line 678, in insert_upsert_implementation
    json_file.raw.seek(0)
OSError: [Errno 29] Illegal seek
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",808008305,
https://github.com/simonw/sqlite-utils/issues/230#issuecomment-778817494,https://api.github.com/repos/simonw/sqlite-utils/issues/230,778817494,MDEyOklzc3VlQ29tbWVudDc3ODgxNzQ5NA==,9599,2021-02-14T18:16:06Z,2021-02-14T18:16:06Z,OWNER,"Types involved:
```
(Pdb) type(json_file.raw)
<class '_io.FileIO'>
(Pdb) type(json_file)
<class 'encodings.utf_8.StreamReader'>
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",808008305,
https://github.com/simonw/sqlite-utils/issues/230#issuecomment-778818639,https://api.github.com/repos/simonw/sqlite-utils/issues/230,778818639,MDEyOklzc3VlQ29tbWVudDc3ODgxODYzOQ==,9599,2021-02-14T18:22:38Z,2021-02-14T18:22:38Z,OWNER,Maybe I shouldn't be using `StreamReader` at all - https://www.python.org/dev/peps/pep-0400/ suggests that it should be deprecated in favour of `io.TextIOWrapper`. I'm using `StreamReader` due to this line: https://github.com/simonw/sqlite-utils/blob/726219c3503e77440975cd15b74d006639feb0f8/sqlite_utils/cli.py#L667-L668,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",808008305,
https://github.com/simonw/sqlite-utils/issues/230#issuecomment-778821403,https://api.github.com/repos/simonw/sqlite-utils/issues/230,778821403,MDEyOklzc3VlQ29tbWVudDc3ODgyMTQwMw==,9599,2021-02-14T18:38:16Z,2021-02-14T18:38:16Z,OWNER,"There are two code paths here that matter:

- For a regular file, can read the first 2048 bytes, then `.seek(0)` before continuing. That's easy.
- `stdin` is harder. I need to read and buffer the first 2048 bytes, then pass an object to `csv.reader()` which will replay that chunk and then play the rest of stdin.

I'm a bit stuck on the second one. Ideally I could use something like `itertools.chain()` but I can't find an alternative for file-like objects.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",808008305,
https://github.com/simonw/sqlite-utils/issues/230#issuecomment-778824361,https://api.github.com/repos/simonw/sqlite-utils/issues/230,778824361,MDEyOklzc3VlQ29tbWVudDc3ODgyNDM2MQ==,9599,2021-02-14T18:59:22Z,2021-02-14T18:59:22Z,OWNER,"I think I've got it. I can use `io.BufferedReader()` to get an object I can run `.peek(2048)` on, then wrap THAT in `io.TextIOWrapper`:

```python
    encoding = encoding or ""utf-8""
    buffered = io.BufferedReader(json_file, buffer_size=4096)
    decoded = io.TextIOWrapper(buffered, encoding=encoding, line_buffering=True)
    if pk and len(pk) == 1:
        pk = pk[0]
    if csv or tsv:
        if sniff:
            # Read first 2048 bytes and use that to detect
            first_bytes = buffered.peek(2048)
            print('first_bytes', first_bytes)
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",808008305,
https://github.com/simonw/sqlite-utils/issues/230#issuecomment-778827570,https://api.github.com/repos/simonw/sqlite-utils/issues/230,778827570,MDEyOklzc3VlQ29tbWVudDc3ODgyNzU3MA==,9599,2021-02-14T19:24:20Z,2021-02-14T19:24:20Z,OWNER,Here's the implementation in Python: https://github.com/python/cpython/blob/63298930fb531ba2bb4f23bc3b915dbf1e17e9e1/Lib/csv.py#L204-L225,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",808008305,