Podcast
Questions and Answers
What is the primary purpose of a software library in Python?
What is the primary purpose of a software library in Python?
- To reinvent the wheel
- To provide a collection of pre-written code (correct)
- To replace the Python interpreter
- To create a new programming language
What are the two ways to import a Python library?
What are the two ways to import a Python library?
- Importing the whole library with an alias or importing a specific object
- Importing the whole library with an alias or importing a specific function (correct)
- Importing the whole library or importing a specific object
- Importing the whole library or importing a specific function
What is the primary use of the NumPy library in Python?
What is the primary use of the NumPy library in Python?
- For model deployment
- For data mining and data scraping
- For creating and manipulating N-dimensional arrays (correct)
- For data visualization
What is the purpose of the np.reshape function in NumPy?
What is the purpose of the np.reshape function in NumPy?
What is the dimension of a 2D NumPy array?
What is the dimension of a 2D NumPy array?
What will happen if you try to reshape a 12-element 1D array into a 4x4 2D array?
What will happen if you try to reshape a 12-element 1D array into a 4x4 2D array?
What is the method to display the first and last 5 rows of a DataFrame?
What is the method to display the first and last 5 rows of a DataFrame?
How can you create a DataFrame from a csv file?
How can you create a DataFrame from a csv file?
What is the attribute of an Iris flower characterized by the length in centimeters?
What is the attribute of an Iris flower characterized by the length in centimeters?
How can you save a DataFrame to a csv file?
How can you save a DataFrame to a csv file?
How many Iris species are in the Iris sample data?
How many Iris species are in the Iris sample data?
What is the main library used for dealing with numeric and string data?
What is the main library used for dealing with numeric and string data?
What is the purpose of the 'describe' function in Pandas Series?
What is the purpose of the 'describe' function in Pandas Series?
What is the default name of the first column in a Pandas Series?
What is the default name of the first column in a Pandas Series?
How can you access a value in a Pandas Series using a custom index?
How can you access a value in a Pandas Series using a custom index?
What is the purpose of the 'read_csv' function in Pandas?
What is the purpose of the 'read_csv' function in Pandas?
What is a Pandas DataFrame?
What is a Pandas DataFrame?
What is the purpose of the np.transpose function in NumPy?
What is the purpose of the np.transpose function in NumPy?
What is the output of np.sort(arr_2D,axis=1)?
What is the output of np.sort(arr_2D,axis=1)?
What does np.sum(grades,axis=1) calculate?
What does np.sum(grades,axis=1) calculate?
What does grades[0,0] access in the array?
What does grades[0,0] access in the array?
What does grades[0:2] access in the array?
What does grades[0:2] access in the array?
What does grades[:,0] access in the array?
What does grades[:,0] access in the array?
What does grades[:,-1] access in the array?
What does grades[:,-1] access in the array?
What is the purpose of the reshape function in NumPy?
What is the purpose of the reshape function in NumPy?
What is the output of np.min(grades,axis=1)?
What is the output of np.min(grades,axis=1)?
What is the main difference between NumPy arrays and Pandas Series/DataFrames?
What is the main difference between NumPy arrays and Pandas Series/DataFrames?
In DataFrames, which statistics are calculated by column?
In DataFrames, which statistics are calculated by column?
What is the purpose of the describe()
function?
What is the purpose of the describe()
function?
How can you calculate the mean of a DataFrame?
How can you calculate the mean of a DataFrame?
What is the output of data.to_numpy()
?
What is the output of data.to_numpy()
?
How can you convert a NumPy array into a DataFrame?
How can you convert a NumPy array into a DataFrame?
What is the purpose of the iloc[]
function?
What is the purpose of the iloc[]
function?
What is the output of data.iloc[:, 0:4].to_numpy()
?
What is the output of data.iloc[:, 0:4].to_numpy()
?
What is the purpose of the head()
function?
What is the purpose of the head()
function?
How can you add columns to a DataFrame?
How can you add columns to a DataFrame?
What is the purpose of the std()
function?
What is the purpose of the std()
function?
Study Notes
NumPy Array
- Importing NumPy:
import numpy as np
- Creating a 1D array:
arr = np.array([1,2,3,4,5,6,7,8,9,10,11,12])
- Reshaping a 1D array into a 2D array:
arr_2D = arr.reshape(4,3)
Transposing NumPy Arrays
- Transposing a 2D array:
arr_2D_transposed = np.transpose(arr_2D)
NumPy Sorting
- Sorting a 2D array:
np.sort(arr_2D, axis=None)
(sorts the whole array) - Row-wise sorting:
np.sort(arr_2D, axis=1)
- Column-wise sorting:
np.sort(arr_2D, axis=0)
NumPy Calculation Functions
- Summation:
- Row-wise:
grades.sum(axis=1)
- Column-wise:
grades.sum(axis=0)
- All grades:
grades.sum(axis=None)
- Row-wise:
- Minimum:
- Row-wise:
grades.min(axis=1)
- Column-wise:
grades.min(axis=0)
- All grades:
grades.min(axis=None)
- Row-wise:
Indexing and Slicing
- Accessing individual elements:
grades[row index, col index]
- Selecting one row:
grades[row index]
- Selecting multiple rows:
grades[row index from : row index to]
- Selecting a subset of columns:
grades[:,0]
(selects all rows, column 0) - Selecting a subset of columns:
grades[:, 0:2]
(selects all rows, columns 0, 1) - Negative indices:
grades[:, -1]
(accesses the last column)
Pandas: Series and DataFrames
- Creating a Series:
grades = pd.Series([87, 100, 94])
- Creating a DataFrame:
grades = pd.DataFrame([87, 100, 94], index=['First', 'Second', 'final'])
- Accessing Series using string indices:
grades['First']
DataFrames
- Creating a DataFrame from a file:
myDataFrame = pd.read_csv("myfile.csv")
- Displaying the first and last 5 rows:
myDataFrame.head()
andmyDataFrame.tail()
- Statistics:
- Mean, min, max, std, var:
data.describe()
- Count, mean, min, max, std:
data.mean()
,data.min()
,data.max()
,data.std()
- Mean, min, max, std, var:
DataFrames and NumPy
- Converting a DataFrame to a NumPy array:
numpy_from_dataFrame = data.to_numpy()
- Converting a NumPy array to a DataFrame:
dataFrame_from_numpy = pd.DataFrame(numpy_from_dataFrame, columns = […])
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Description
Learn about popular Python libraries, including Numpy and Pandas, and how they can be used to improve your programming experience. This quiz covers the basics of Python libraries and their applications.