| name | polars-common-issues |
| description | Sub-skill of polars: Common Issues. |
| version | 1.0.0 |
| category | data-analysis |
| type | reference |
| scripts_exempt | true |
Common Issues
Common Issues
Issue: Out of Memory
result = lf.collect(streaming=True)
lf.sink_parquet("output.parquet")
for chunk in pl.read_csv_batched("large.csv", batch_size=100000):
process(chunk)
Issue: Slow Performance
print(lf.explain(optimized=True))
result = lf.profile()
print(result[1])
Issue: Type Mismatch in Join
df1 = df1.with_columns(pl.col("id").cast(pl.Int64))
df2 = df2.with_columns(pl.col("id").cast(pl.Int64))
result = df1.join(df2, on="id")
Issue: Date Parsing Errors
df = df.with_columns([
pl.col("date_str").str.strptime(pl.Date, "%Y-%m-%d"),
pl.col("datetime_str").str.strptime(pl.Datetime, "%Y-%m-%d %H:%M:%S")
])