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5 Ways to Manipulate Pandas Dataframes

Pandas is a great library in Python that expedites the data analysis and exploration process. Pandas also is that it provides a variety of functions and methods for data manipulation. In this blog, I wanted to quickly discuss and show a few useful pandas methods/functions, which can come in handy during your daily work.


Installation


To install pandas, you just need to run pip install pandas in your terminal . Then we can import pandas as pd.


pip install pandas 

to import it


import pandas as pd

after installing and import our library now we can start our desired operations with pandas.


now we need to insert our Dataframe as following


import pandas as pd
import numpy as np
data = {'product_name': ['laptop', 'printer', 'tablet', 'desk', 'chair'],
        'price': [1200, 150, 300, 450, 200]
        }
        
 df = pd.DataFrame(data)

print(df)       








1. Sorting DataFrame

we can sort the data frame in ascending or descending in pandas and that by using function sort_values().


And we can applying as here


Input:


df.sort_values(by=['price'], ascending=True)

output:











2. Apply Function


this function is used to apply a function along an axis of dataframe

whether it can be row as (axis=0) or column (axis=1).


input:


def double(a):
    return 2*a
 
df['price'] = df['price'].apply(double)
 
# Reading Dataframe
df

Output:












3. Cut Function


The cut() function is used to bin values into discrete intervals. we use cut when you need to segment and sort data values into bins . it only works with arrays.


Input:


pd.cut(np.array([2, 7, 5, 4, 6, 8]), 3)

Output:


[(1.994, 4.0], (6.0, 8.0], (4.0, 6.0], (1.994, 4.0], (4.0, 6.0], (6.0, 8.0]]
Categories (3, interval[float64]): [(1.994, 4.0] < (4.0, 6.0] < (6.0, 8.0]]

4. Explode in Dataframe


explode() method I, t used to transform each element of a list-like to a row, replicating index values.


Input :


df1 = pd.DataFrame(data={"id": [1, 2], 
                        "values": [[1, 2, 3], [4, 5, 6]]})
df1

Output:






now we apply the explode in our dataframe


Input :


df1.explode("values", ignore_index=True)

Output:














5. Indexing and Slicing


Here .loc is label base and .iloc is integer position based methods used for slicing and indexing of data.

we will apply on the same dataframe that we used in the first example.


Input:

print(df.loc[0:4, 'product_name'])
 
# Printing all the rows with price column

print(df.loc[:, 'price'])
 
# Printing only first rows having name.
print(df.iloc[0, 0:2])
 
# Printing first 3 rows having product name and price .
print(df.iloc[0:3, 0:3])
 
# Printing all rows having  product name & price 
print(df.iloc[:, 0:2])

Output























You can find the code used for this article on my Github. Thank you for reading. Please let me know if you have any feedback.


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