When printing a polars data frame, pl.Duration are printed in a "human format" by default. What function is used to do this conversion? Is it possible to use it? Trying "{}".format() returns something readable but not as good.
import polars as pl
data = {"end": ["2024/11/13 10:28:00",
"2024/10/10 10:10:10",
"2024/09/13 09:12:29",
"2024/08/31 14:57:02",
],
"start": ["2024/11/13 10:27:33",
"2024/10/10 10:01:01",
"2024/09/13 07:07:07",
"2024/08/25 13:48:28",
]
}
df = pl.DataFrame(data)
df = df.with_columns(
pl.col("end").str.to_datetime(),
pl.col("start").str.to_datetime(),
)
df = df.with_columns(
duration = pl.col("end") - pl.col("start"),
)
df = df.with_columns(
pl.col("duration").map_elements(lambda t: "{}".format(t), return_dtype=pl.String()).alias("duration_str")
)
print(df)
shape: (4, 4)
┌─────────────────────┬─────────────────────┬──────────────┬─────────────────┐
│ end ┆ start ┆ duration ┆ duration_str │
│ --- ┆ --- ┆ --- ┆ --- │
│ datetime[μs] ┆ datetime[μs] ┆ duration[μs] ┆ str │
╞═════════════════════╪═════════════════════╪══════════════╪═════════════════╡
│ 2024-11-13 10:28:00 ┆ 2024-11-13 10:27:33 ┆ 27s ┆ 0:00:27 │
│ 2024-10-10 10:10:10 ┆ 2024-10-10 10:01:01 ┆ 9m 9s ┆ 0:09:09 │
│ 2024-09-13 09:12:29 ┆ 2024-09-13 07:07:07 ┆ 2h 5m 22s ┆ 2:05:22 │
│ 2024-08-31 14:57:02 ┆ 2024-08-25 13:48:28 ┆ 6d 1h 8m 34s ┆ 6 days, 1:08:34 │
└─────────────────────┴─────────────────────┴──────────────┴─────────────────┘
Polars 1.14.0 added Duration type support to .dt.to_string()
It can produce iso and polars formatted strings.
pl.select(
pl.duration(hours=1, minutes=2).dt.to_string() # format="iso"
).item()
# 'PT1H2M'
pl.select(
pl.duration(hours=1, minutes=2).dt.to_string(format="polars")
).item()
# '1h 2m'