当字符串中有 substring 时，检查并返回 Boolean

Question

Hi I am searching only the exact substring from string column and return True/False.

Row-3,4,5 has sting 'abc' (case-sensitive) but when i tried to return it returns TRUE for all rows
Below is code i have tried.

df['try_output'] = df['String1'].str.contains('ABC',case = False)

Is there any modification in above statement to get output column ' Required_Output '

Answer 1

I don't think str.contains is what you are looking for here, rather, you are looking for an exact match that will not consider upper / lower cases. Therefore, you can simply convert to upper, str.upper() , and check whether it equals to 'ABC':

df['output'] = df.string_1.str.upper() == 'ABC'

print(df)

  string_1  output
0      ABC    True
1      abc    True
2   XYZabc   False
3   XyzABC   False
4  ABCqqqq   False
5      AbC    True
6      aBC    True

---

It's logical why your code returns everything TRUE - all of your rows contain 'abc', especially when you specify not to care about upper cases ( case = False )

Answer 2

Use str.fullmatch ( Pandas >= 1.1.0 ) without any conversion:

df['output'] = df['string_1'].str.fullmatch('abc', case=False)
print(df)

# Output:
  string_1  output
0      ABC    True
1      abc    True
2   XYZabc   False
3   XyzABC   False
4  ABCqqqq   False
5      AbC    True
6      aBC    True