selecting column by index pandas code example

Example 1: slicing in pandas

# iloc[row slicing, column slicing]
surveys_df.iloc[0:3, 1:4]

Example 2: select columns in pandas df

In [8]: age_sex = titanic[["Age", "Sex"]]

In [9]: age_sex.head()
Out[9]: 
    Age     Sex
0  22.0    male
1  38.0  female
2  26.0  female
3  35.0  female
4  35.0    male

Example 3: loc and iloc in pandas

iloc - default indexes (system generated)
loc - table indexes or we manually given indexes

Example 4: get column index pandas

df = pd.read_csv('thanksgiving_w_age_income.csv')

# Obtain Column Indices:
gravy = df.columns.get_loc("Do you typically have gravy?")
meet_friends = df.columns.get_loc('Have you ever tried to meet up with hometown friends on Thanksgiving night?')
friendsgiving = df.columns.get_loc('Have you ever attended a "Friendsgiving?"')

Example 5: loc and iloc in pandas

iloc slicing gives all the data upto the position that is passed as argument
loc gives all the data upto the label that is passed as argument
n = pd.Series([1,2,3,4],index = [0,1,2,3])
print("With iloc we got")
print(n.iloc[:2])
print("With loc we got")
print(n.loc[:2])

<Output>
With iloc we got
0    1
1    2
dtype: int64
With loc we got
0    1
1    2
2    3
dtype: int64