Closed
Description
Pandas version checks
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I have checked that this issue has not already been reported.
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I have confirmed this bug exists on the latest version of pandas.
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I have confirmed this bug exists on the main branch of pandas.
Reproducible Example
In [1]: import pandas as pd
df =
In [2]: df = pd.DataFrame()
In [3]: df.diff(0.5)
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-3-03698d8a038c> in ?()
----> 1 df.diff(0.5)
~/.miniconda3/envs/snowpark/lib/python3.8/site-packages/pandas/core/frame.py in ?(self, periods, axis)
9216 is_float(periods)
9217 # error: "int" has no attribute "is_integer"
9218 and periods.is_integer() # type: ignore[attr-defined]
9219 ):
-> 9220 raise ValueError("periods must be an integer")
9221 periods = int(periods)
9222
9223 axis = self._get_axis_number(axis)
ValueError: periods must be an integer
In [4]: series = pd.Series()
<ipython-input-4-2b0f0f5d39e8>:1: FutureWarning: The default dtype for empty Series will be 'object' instead of 'float64' in a future version. Specify a dtype explicitly to silence this warning.
series = pd.Series()
In [5]: series.diff(0.5)
Out[5]: Series([], dtype: float64)
In [6]: df.diff('1')
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-6-ffa50df92031> in ?()
----> 1 df.diff('1')
~/.miniconda3/envs/snowpark/lib/python3.8/site-packages/pandas/core/frame.py in ?(self, periods, axis)
9216 is_float(periods)
9217 # error: "int" has no attribute "is_integer"
9218 and periods.is_integer() # type: ignore[attr-defined]
9219 ):
-> 9220 raise ValueError("periods must be an integer")
9221 periods = int(periods)
9222
9223 axis = self._get_axis_number(axis)
ValueError: periods must be an integer
In [7]: series.diff('1')
Out[7]: Series([], dtype: float64)
In [8]: series.diff('a')
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
Cell In[8], line 1
----> 1 series.diff('a')
File ~/.miniconda3/envs/snowpark/lib/python3.8/site-packages/pandas/core/series.py:2903, in Series.diff(self, periods)
2818 @doc(
2819 klass="Series",
2820 extra_params="",
(...)
2866 )
2867 def diff(self, periods: int = 1) -> Series:
2868 """
2869 First discrete difference of element.
2870
(...)
2901 {examples}
2902 """
-> 2903 result = algorithms.diff(self._values, periods)
2904 return self._constructor(result, index=self.index).__finalize__(
2905 self, method="diff"
2906 )
File ~/.miniconda3/envs/snowpark/lib/python3.8/site-packages/pandas/core/algorithms.py:1699, in diff(arr, n, axis)
1679 def diff(arr, n: int, axis: int = 0):
1680 """
1681 difference of n between self,
1682 analogous to s-s.shift(n)
(...)
1696 shifted
1697 """
-> 1699 n = int(n)
1700 na = np.nan
1701 dtype = arr.dtype
ValueError: invalid literal for int() with base 10: 'a'
### Issue Description
Series.diff doesn't validate the `periods` argument, while `df.diff` does.
### Expected Behavior
I think that Series.diff should also validate and throw the same exceptions as df.diff.
### Installed Versions
<details>
INSTALLED VERSIONS
------------------
commit : 2e218d10984e9919f0296931d92ea851c6a6faf5
python : 3.8.18.final.0
python-bits : 64
OS : Darwin
OS-release : 23.2.0
Version : Darwin Kernel Version 23.2.0: Wed Nov 15 21:55:06 PST 2023; root:xnu-10002.61.3~2/RELEASE_ARM64_T6020
machine : x86_64
processor : i386
byteorder : little
LC_ALL : None
LANG : en_US.UTF-8
LOCALE : en_US.UTF-8
pandas : 1.5.3
numpy : 1.24.3
pytz : 2023.3.post1
dateutil : 2.8.2
setuptools : 68.0.0
pip : 23.2.1
Cython : None
pytest : 7.4.3
hypothesis : None
sphinx : 5.0.2
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : None
pymysql : None
psycopg2 : None
jinja2 : 3.1.2
IPython : 8.12.3
pandas_datareader: None
bs4 : 4.12.2
bottleneck : 1.3.5
brotli : None
fastparquet : None
fsspec : None
gcsfs : None
matplotlib : 3.7.3
numba : None
numexpr : 2.8.4
odfpy : None
openpyxl : None
pandas_gbq : None
pyarrow : 10.0.1
pyreadstat : None
pyxlsb : None
s3fs : None
scipy : None
snappy : None
sqlalchemy : None
tables : None
tabulate : None
xarray : None
xlrd : None
xlwt : None
zstandard : None
tzdata : 2023.3
</details>