NumPy is the fundamental package for scientific computing in Python. It provides a high - performance multi - dimensional array object, and tools for working with these arrays. NumPy arrays are homogeneous, meaning they can only contain elements of the same data type. This property allows for efficient storage and computation.
import numpy as np
# Create a simple NumPy array
arr = np.array([1, 2, 3, 4, 5])
print(arr)
Pandas is a library that provides data structures like DataFrames and Series. A Series is a one - dimensional labeled array, while a DataFrame is a two - dimensional labeled data structure with columns of potentially different types. Pandas offers a wide range of functions for data manipulation, including data cleaning, aggregation, and analysis.
import pandas as pd
# Create a simple Pandas Series
s = pd.Series([1, 3, 5, np.nan, 6, 8])
print(s)
NumPy is not a part of Pandas in the sense that NumPy is an independent library. However, Pandas is built on top of NumPy. Pandas heavily relies on NumPy arrays for its internal data storage. For example, the underlying data in a Pandas Series or DataFrame is often stored as a NumPy array. This allows Pandas to take advantage of the performance benefits of NumPy arrays.
We can create Pandas objects using NumPy arrays.
import numpy as np
import pandas as pd
# Create a NumPy array
np_arr = np.array([[1, 2, 3], [4, 5, 6]])
# Create a DataFrame from the NumPy array
df = pd.DataFrame(np_arr, columns=['A', 'B', 'C'])
print(df)
We can also use NumPy functions on Pandas data. Since the underlying data in Pandas is often a NumPy array, many NumPy functions can be directly applied.
import numpy as np
import pandas as pd
# Create a Pandas Series
s = pd.Series([1, 2, 3, 4, 5])
# Apply a NumPy function (square root) to the Series
result = np.sqrt(s)
print(result)
When dealing with missing data, we can use both Pandas and NumPy. Pandas provides functions to handle missing values, and NumPy can be used for numerical operations on the cleaned data.
import numpy as np
import pandas as pd
# Create a DataFrame with missing values
df = pd.DataFrame({'A': [1, 2, np.nan], 'B': [4, np.nan, 6]})
# Fill missing values with the mean using Pandas
df_filled = df.fillna(df.mean())
# Calculate the sum of each column using NumPy
column_sums = np.sum(df_filled.values, axis = 0)
print(column_sums)
We can perform data aggregation using Pandas and then use NumPy for further numerical analysis.
import numpy as np
import pandas as pd
# Create a DataFrame
df = pd.DataFrame({'Group': ['A', 'A', 'B', 'B'], 'Value': [1, 2, 3, 4]})
# Group the data by 'Group' and calculate the sum using Pandas
grouped = df.groupby('Group').sum()
# Calculate the mean of the aggregated values using NumPy
mean_value = np.mean(grouped.values)
print(mean_value)
Since Pandas is built on NumPy, using NumPy functions whenever possible can significantly improve performance. For example, using NumPy’s vectorized operations instead of Python loops can speed up the code.
import numpy as np
import pandas as pd
# Create a large DataFrame
df = pd.DataFrame(np.random.randn(1000000, 5))
# Using a NumPy function for a column operation
df['new_col'] = np.sqrt(df['0'])
It is important to write code that is easy to understand. When using both Pandas and NumPy, use descriptive variable names and add comments to explain the purpose of each step.
import numpy as np
import pandas as pd
# Create a DataFrame
df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]})
# Calculate the sum of column 'A' using NumPy
# This step calculates the sum of values in column 'A' for further analysis
sum_A = np.sum(df['A'].values)
print(sum_A)
In conclusion, while NumPy is not part of Pandas in the traditional sense, Pandas is built on top of NumPy. The two libraries are highly complementary, and understanding their relationship can greatly enhance your data analysis capabilities in Python. By leveraging the strengths of both NumPy and Pandas, you can write efficient, readable, and powerful data analysis code.