Get Column Index from Column Name in Python Pandas

Get column index from column name in python pandas

Sure, you can use .get_loc():

In [45]: df = DataFrame({"pear": [1,2,3], "apple": [2,3,4], "orange": [3,4,5]})

In [46]: df.columns
Out[46]: Index([apple, orange, pear], dtype=object)

In [47]: df.columns.get_loc("pear")
Out[47]: 2

although to be honest I don't often need this myself. Usually access by name does what I want it to (df["pear"], df[["apple", "orange"]], or maybe df.columns.isin(["orange", "pear"])), although I can definitely see cases where you'd want the index number.

Retrieve name of column from its Index in Pandas

I think you need index columns names by position (python counts from 0, so for fourth column need 3):

colname = df.columns[pos]

Sample:

df = pd.DataFrame({'A':[1,2,3],
                   'B':[4,5,6],
                   'C':[7,8,9],
                   'D':[1,3,5],
                   'E':[5,3,6],
                   'F':[7,4,3]})

print (df)
   A  B  C  D  E  F
0  1  4  7  1  5  7
1  2  5  8  3  3  4
2  3  6  9  5  6  3

pos = 3
colname = df.columns[pos]
print (colname)
D

---

pos = [3,5]
colname = df.columns[pos]
print (colname)
Index(['D', 'F'], dtype='object')

Pandas index column title or name

You can just get/set the index via its name property

In [7]: df.index.name
Out[7]: 'Index Title'

In [8]: df.index.name = 'foo'

In [9]: df.index.name
Out[9]: 'foo'

In [10]: df
Out[10]: 
         Column 1
foo              
Apples          1
Oranges         2
Puppies         3
Ducks           4

Pandas: Get cell value by row index and column name

Use .loc to get rows by label and .iloc to get rows by position:

>>> df.loc[3, 'age']
23

>>> df.iloc[2, df.columns.get_loc('age')]
23

More about Indexing and selecting data

Get column names with corresponding index in python pandas

Simpliest is add pd.Series constructor:

pd.Series(list(df.columns))

Or convert columns to Series and create default index:

df.columns.to_series().reset_index(drop=True)

Or:

df.columns.to_series(index=False)

Pandas return index and column name based on condition

One option is to reshape the data and filter with the booleans:

df.lt(.25).stack().loc[lambda df: df].index.to_list()

[('A', 'E'), ('C', 'D')]

Get the index name AND column name for each cell in pandas dataframe

you could try melting (pd.melt) your dataframe while keeping the index as your variable :

df = pd.DataFrame(
    np.random.choice([True, False], (5, 5)), columns=list("abcde"), index=list("fghij")
)
#   a   b   c   d   e
# f False   True    True    True    False
# g True    True    False   False   True
# h False   True    True    False   False
# i True    True    False   False   False
# j True    True    False   True    True

df.reset_index().melt(id_vars='index').query('value == True')

outputs :

  index variable value
1   g   a   True
3   i   a   True
4   j   a   True
5   f   b   True
6   g   b   True
7   h   b   True
8   i   b   True
9   j   b   True
10  f   c   True
12  h   c   True
15  f   d   True
19  j   d   True
21  g   e   True
24  j   e   True

Trying to get the column indexes with the column names in pandas

i = 0
for col in df.columns:
    print(i, col)
    i += 1

Efficient way to get indices of column-labels from pd.DataFrame

short_way = [df.columns.get_loc(col) for col in query_cols]
print(sorted(short_way))
# outputs [0, 2, 5, 6]

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