Hello, students! Today, we're exploring the pandas DataFrame, a powerhouse structure in data analysis with Python. We'll contrast it with NumPy arrays and teach you how to build a DataFrame. Additionally, we'll delve into its integral parts and data types.

The pandas library is Python's solution for tabular data operations, packing more punch for data analysis than NumPy, which is skewed towards numerical computations. Pandas houses two fundamental data structures: the Series (1D) and the DataFrame (2D). Often, the DataFrame is the go-to choice. Let's start by importing pandas:

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1import pandas as pd

Here, pd serves as a standard alias for pandas.

Building a DataFrame in pandas is straightforward. It can be created from a dictionary, list, or NumPy array. Here's an example of creating a DataFrame from a dictionary:

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1student_data = {  
2    'Name': ['Sara', 'Ray', 'John'],
3    'Age': [15, 16, 17],
4}
5
6df = pd.DataFrame(student_data)
7
8print(df)
9
10'''Output:
11   Name  Age
120  Sara   15
131   Ray   16
142  John   17
15'''

In the student_data dictionary, each (key, value) pair becomes a DataFrame column. The DataFrame automatically assigns an index (0-2) to each row, but we can also specify our own if we choose to do so.

Adding a new column to an existing DataFrame is straightforward: just like with dictionary, simply refer to a new key and assign an array to it. Let's add information about student's grades to our data:

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1df['Grade'] = [9, 10, 7]
2
3print(df)
4
5'''Output:
6   Name  Age  Grade
70  Sara   15      9
81   Ray   16     10
92  John   17      7
10'''

The 'Grade' column has been successfully added to the DataFrame.

A DataFrame consists of three components: data, index, and columns. Pandas neatly organize data into rows and columns — each row is a record, and each column is a feature (such as Name, Age, or Grade). The index, much like the index of a book, aids in data location. Columns serve as labels for the features in our data. Let's analyze these components with our student data:

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1print(df.index)  # Output: RangeIndex(start=0, stop=3, step=1)
2print(df.columns)  # Output: Index(['Name', 'Age', 'Grade'], dtype='object') 

Our dataset contains row labels (index) from 0 to 2 and column labels (columns) of 'Name', 'Age', and 'Grade'.

One of the useful features of pandas DataFrame is its flexibility in accessing individual columns of data. You can select a single column, much like how you access a dictionary item by its key. Let's use our student_data DataFrame again:

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1print(df['Name'])
2
3'''Output:
40    Sara
51     Ray
62    John
7Name: Name, dtype: object
8'''

As you can see, we now only have the 'Name' column content. Notice that pandas kept the index intact to retain information about the original rows.

To access multiple columns at once, pass a list with column names:

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1print(df[['Name', 'Grade']])
2
3'''Output:
4   Name  Grade
50  Sara      9
61   Ray     10
72  John     11
8'''

Adding a list of columns as input, we obtain a new DataFrame that only includes the students' 'Name' and 'Grade'.

Remember: when handling a single column, pandas will return a Series. When dealing with multiple columns, pandas will return a DataFrame. Any new DataFrame or Series changes will not affect the original data.

The strength of a DataFrame lies in its ability to accommodate multiple data types. Using the DataFrame.dtypes property, we can ascertain the data type of each column. Let's look at the data types of out DataFrame:

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1print(df.dtypes)
2
3Name     object
4Age       int64
5Grade     int64
6dtype: object

Note, that strings are represented as the object data type.

Unlike NumPy arrays, which harbor single-type data, pandas DataFrames can handle and manipulate different data types.

And there we have it! We've traversed the fascinating terrain of the pandas DataFrame. We've compared it with NumPy arrays, learned how to build a DataFrame, and explored its structure and diverse data types. Now, it's time to shift gears to some hands-on practice. You'll master the art of creating pandas' DataFrame, solidifying your understanding and bolstering your confidence.