如何定位 pandas Dataframe 中特定值的出现

Question

I want to locate a specific value which can occur in multiple columns. In my case it's "False". I know how to search "False" in individual columns as

df.loc[df['column1']==False]
df.loc[df['column2']==False]

Is there a way to find all at once?

Unnamed: 0  Incident ID CR Number   Victims Zip Code    Address Number  Latitude    Longitude   Year    Month   Day
0   False   False   True    True    True    True    True    True    True    True    True
1   False   True    False   False   True    True    True    True    True    True    True
2   True    True    True    True    True    True    False   True    True    True    True
3   True    True    False   True    True    True    True    True    True    True    True
4   True    True    True    True    True    True    True    True    False   True    True

I want to see their locations.Hopefully something like

df.applymap.loc(False)

Answer 1

If you want to get the indices stack , then slice:

s = df.stack()
s[s.eq(False)].index

Or if you only have True / False :

s[~s].index

In one line:

df.stack().loc[lambda s: ~s].index

If you want to assign value(s) on the False positions, a simple boolean indexing will do:

df[df.eq(False)] = 'X'`

# or, if only True/False in the df 
df[~df] = 'X'`