DOC: Negative values ​​of n in pandas.DataFrame.head

[jmonti-gh]

Pandas version checks

• I have checked that the issue still exists on the latest versions of the docs on main here

Location of the documentation

https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.head.html

Documentation problem

When you explain negative values ​​of n you indicate an incorrect equivalence of the indexing of the DataFrame.
It says: "For negative values of n, this function returns all rows except the last |n| rows, equivalent to df[:n]."

Suggested fix for documentation

And it should say:
"..., equivalent to df[:-n]."

[rhshadrach]

Thanks for the report, but I do not think your suggested fix is correct.

df = pd.DataFrame({"a": [0, 1, 2, 3]})

# n here is -1
print(df.head(-1))
#    a
# 0  0
# 1  1
# 2  2

# This is df[:n]
print(df[:-1])
#    a
# 0  0
# 1  1
# 2  2

# This is df[:-n]
print(df[:-(-1)])
#    a
# 0  0

[jmonti-gh]

Thanks for your clarification Richard, I was indeed wrong. I was thinking something like df[:-|n|]