Pandas DataFrames

• What is a DataFrame?

A Pandas DataFrame is a 2 dimensional data structure, like a 2 dimensional array, or a table with rows and columns.

 

Example

You are tasked with creating a Pandas DataFrame to represent student information. The DataFrame should include columns for "StudentID," "Name," "Age," and "Grade." Create a Pandas DataFrame with the following data.

| StudentID | Name     | Age | Grade |
|-----------|----------|-----|-------|
| 101       | Alice    | 20  | A     |
| 102       | Bob      | 22  | B     |
| 103       | Charlie  | 21  | B     |
| 104       | David    | 23  | C     |
| 105       | Emma     | 20  | A     |

Write Python code to create this DataFrame and display its contents.

import pandas as pd

data = {
    "StudentID": [101, 102, 103, 104, 105],
    "Name": ["Alice", "Bob", "Charlie", "David", "Emma"],
    "Age": [20, 22, 21, 23, 20],
    "Grade": ["A", "B", "B", "C", "A"]
}

df = pd.DataFrame(data)
print(df)

 

• Locate Row 

Pandas use the loc attribute to return one or more specified row(s).

 

Example 

Return row 0.

import pandas as pd

data = {
  "calories": [420, 380, 390],
  "duration": [50, 40, 45]
}

#load data into a DataFrame object:
df = pd.DataFrame(data)

print(df)

  calories  duration
  0       420        50
  1       380        40
  2       390        45

 

• Named Indexes

With the index argument, you can name your own indexes.

 

Example 

Add a list of names to give each row a name.

import pandas as pd

data = {
  "calories": [420, 380, 390],
  "duration": [50, 40, 45]
}

df = pd.DataFrame(data, index = ["day1", "day2", "day3"])

print(df)

 		calories  duration
  day1       420        50
  day2       380        40
  day3       390        45

 

• Locate Named Indexes

Use the named index in the loc attribute to return the specified rows. 

 

Example 

Return "berry". 

print (df.loc["berry"])