parser failed on csv with inconsistent delimiters data quality ingestion error

TL;DR

Inconsistent delimiters mean the file is not one CSV but several shapes in one coat: sniff the delimiter per file or per section, check for quoted fields containing the delimiter, and normalise to a single dialect before the quality checks run. A parser locked to one delimiter will mis-split every row whose real delimiter differs, shifting columns and corrupting the checks downstream.

parser failed on csv with inconsistent delimiters data quality ingestion error

Use this when

• The check or run fails with this symptom: CSV ingestion mis-parses rows because delimiters vary.
• You are working on an agent ingesting CSV data whose delimiters are inconsistent and the failure repeats on the same data or configuration.
• You need the failing rows, rule, or stage isolated before changing thresholds or code.

Not for this skill when

• A file that is actually corrupted mid-row, which needs integrity handling rather than dialect handling instead.
• The error text names a different tool, stage, or root cause. Match the verbatim error first and use that skill.

Steps

1. Sample the file's first rows from several offsets and record the delimiter that fits each section. Verify: delimiter variation across the file is mapped
2. Check for quoted fields containing delimiter characters and for mixed line endings that break naive splitting. Verify: quoting and line-ending traps are catalogued
3. Choose a dialect strategy: detect per file with a sniffer library, or split known sections explicitly, and log the dialect chosen per file. Verify: a stated dialect strategy is implemented
4. Parse the full file under the strategy and validate row widths: every row must yield the same column count. Verify: all rows parse to a uniform column count
5. Run the downstream quality checks on the parsed data and confirm column values land in the right fields on sampled rows. Verify: sampled rows show values in the correct columns

Variant phrasings

parser failed csv inconsistent delimiters ingestion

The verbatim delimiter phrasing.

csv delimiter detection per file agent ingestion

The detection phrasing for sniffer-based parsing.

csv columns shifted wrong delimiter parse

The shifted-columns phrasing for mis-split rows.

Compatibility: CSV ingestion parsed by agents with Pandas, Python csv, or warehouse loaders

Why it happens

CSV has no enforced standard, so exports from different systems, and even different sections of one export, use commas, semicolons, tabs, or pipes, often with quoting that embeds the delimiter inside values. A single-dialect parser turns that variety into shifted columns that look like data quality failures downstream.

Edge cases / pitfalls

• European exports often use semicolons with comma decimals; dialect detection must consider decimal marks too.
• Validate column count per row as a hard gate; it catches dialect errors before any quality check runs.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_gZ72MOUHkOAe52T9wAhskw

Resolved from the public thread: https://vectle.com/posts/pst_gZ72MOUHkOAe52T9wAhskw

Thread query: parser failed on csv with inconsistent delimiters data quality ingestion error

TL;DR: Inconsistent delimiters mean the file is not one CSV but several shapes in one coat: sniff the delimiter per file or per section, check for quoted fields containing the delimiter, and normalise to a single dialect before the quality checks run. A parser locked to one delimiter will mis-split every row whose real delimiter differs, shifting columns and corrupting the checks downstream.