Pandas - find index of value anywhere in DataFrame

Question

I'm new to Python & Pandas.

I want to find the index of a certain value (let's say security_id) in my pandas dataframe, because that is where the columns start. (There is an unknown number of rows with irrelevant data above the columns, as well as a number of empty 'columns' on the left side.)

As far as I see, the isin method only returns a boolean on whether the value exists, not its index.

How do I find the index of this value?

Answer 1

Get the index for rows matching search term in all columns

search = 'security_id' 
df.loc[df.isin([search]).any(axis=1)].index.tolist()

Rows filtered for matching search term in all columns

search = 'search term' 
df.loc[df.isin([search]).any(axis=1)]

Answer 2

A oneliner solution avoiding explicit loops...

• returning the entire row(s)

  df.iloc[np.flatnonzero((df=='security_id').values)//df.shape[1],:]

• returning row(s) and column(s)

  df.iloc[ np.flatnonzero((df=='security_id').values)//df.shape[1], np.unique(np.flatnonzero((df=='security_id').values)%df.shape[1]) ]

Answer 3

Supposing that your DataFrame looks like the following :

      0       1            2      3    4
0     a      er          tfr    sdf   34
1    rt     tyh          fgd    thy  rer
2     1       2            3      4    5
3     6       7            8      9   10
4   dsf     wew  security_id   name  age
5   dfs    bgbf          121  jason   34
6  dddp    gpot         5754   mike   37
7  fpoo  werwrw          342   jack   31

Do the following :

for row in range(df.shape[0]): # df is the DataFrame
         for col in range(df.shape[1]):
             if df.get_value(row,col) == 'security_id':
                 print(row, col)
                 break