print(data.loc[data['cp']=="34400",:])
      dep                     nom     cp   ...         lat  alt_min  alt_max
13262  34                   Lunel  34400   ...     43.6833        2       53
13263  34              Lunel-Viel  34400   ...     43.6833        6       50
13359  34          Saint-Christol  34400   ...     43.7333       24       92
13384  34              Saint-Just  34400   ...     43.6500        2        9
13391  34  Saint-Nazaire-de-Pézan  34400   ...     43.6333        0        5
13399  34            Saint-Sériès  34400   ...     43.7333       14       68
13405  34             Saturargues  34400   ...     43.7167       16       68
13437  34               Vérargues  34400   ...     43.7167       15       65
13447  34              Villetelle  34400   ...     43.7333       10       67
[9 rows x 12 columns]