Pandas Dataframe issue on engine.get_loc

[shjustinzhang]

If I comment on this one, df = df[~df['Name'].isin(['A'])], the entire code will work.
If I add it in, it will report error as showing below.

I am trying to understand issue over there, so df['Compare'][a] == 'True', 'a' as 0,1,2,3, this format is not recommend ?

--------------------------------------------Error Message------------------------------------------------------

---

KeyError Traceback (most recent call last)
File /lib/python3.10/site-packages/pandas/core/indexes/base.py:3621, in Index.get_loc(self, key, method, tolerance)
3620 try:
-> 3621 return self._engine.get_loc(casted_key)
3622 except KeyError as err:

File /lib/python3.10/site-packages/pandas/_libs/index.pyx:136, in pandas._libs.index.IndexEngine.get_loc()

File /lib/python3.10/site-packages/pandas/_libs/index.pyx:163, in pandas._libs.index.IndexEngine.get_loc()

File pandas/_libs/hashtable_class_helper.pxi:2131, in pandas._libs.hashtable.Int64HashTable.get_item()

File pandas/_libs/hashtable_class_helper.pxi:2140, in pandas._libs.hashtable.Int64HashTable.get_item()

KeyError: 0

The above exception was the direct cause of the following exception:

KeyError Traceback (most recent call last)
Input In [63], in <cell line: 3>()
1 df = df[~df['Name'].isin(['A'])]
3 for a in range(len(df)):
----> 4 if df['Compare'][a] == 'True':
5 df['output'][a] = (df['Size'][a],df['Compare'][a])
7 df

File /lib/python3.10/site-packages/pandas/core/series.py:958, in Series.getitem(self, key)
955 return self._values[key]
957 elif key_is_scalar:
--> 958 return self._get_value(key)
960 if is_hashable(key):
961 # Otherwise index.get_value will raise InvalidIndexError
962 try:
963 # For labels that don't resolve as scalars like tuples and frozensets

--------------------------------------------Code------------------------------------------------------
import pandas as pd
import numpy as np

df = pd.DataFrame({"Name":["A","B","B","C"],
"Str":["f","B","o","C"],
"Size":["66","0x88","32","9"]
})

df['Compare'] = (df['Name'] == df['Str'])
df['Compare'] = df['Compare'].astype(str)
df.insert(4,'output','0')
df = df[['Name','Str','Size','Compare','output']]

df = df[~df['Name'].isin(['A'])]

for a in range(len(df)):
if df['Compare'][a] == 'True':
df['output'][a] = (df['Size'][a],df['Compare'][a])

print(df)

[shjustinzhang]

NVＭ，I figure it out.

df = df[~df['Name'].isin(['A'])]

print(df.iloc[:,3])

for a in range(len(df)):
if df.iloc[a,3] == 'True':
# df['output'][a] = (df['Size'][a],df['Compare'][a])
df.iloc[a,4] = (df.iloc[a,2],df.iloc[a,3])

df