Read a dataset file into a data frame

Reads a CSV or fixed-width file, coercing all columns to character and trimming whitespace. Encoding and delimiter are taken from config. A declared encoding of ASCII (or a formal alias such as US-ASCII) is read as UTF-8: ASCII is a strict subset of UTF-8, so this is lossless, and it protects against deliveries whose non-ASCII bytes appear beyond any sample a sniffer looked at. When the effective encoding is UTF-8 the whole file is validity-scanned before parsing; a delivery that is not valid UTF-8 is read using a single-byte fallback encoding instead, and the mismatch is surfaced by check_file_encoding (QC-16) as a FAIL result rather than crashing the run.

Usage

read_dataset(path, config)

Arguments

path

Character. Path to the file to read.

config

Named list. Merged configuration as returned by load_config. Must include format ("csv" or "fwf"). For CSV files, col_names (an explicit column-name list) and csv_skip (number of leading lines to drop, e.g. a real header row that is being replaced by col_names) are optional and default to using the file's own header and 0L respectively. For FWF files, fwf_widths is required and fwf_col_names and fwf_skip are optional.

Value

A data frame with all columns as character vectors.

Examples

cfg_dir <- system.file("demonstrations/config", package = "dqcheckr")
cfg  <- load_config("starwars_csv", config_dir = cfg_dir)
path <- system.file("demonstrations/data/starwars.csv", package = "dqcheckr")
df   <- read_dataset(path, cfg)