ENV 859 - Geospatial Data Analytics | Fall 2026 | Instructor:
John Fay
1. What is a Data Frame?
- Table of data
- Rows represent observations
- Columns (attributes) must have the same data type
- Cells in the table can be referenced by intrinsic location (iloc) or by row and column labels (indices)
2. Loading data into a Data Frame
read_csv()
- Quite customizable
- Has defaults on how data are read in, which can be overridden (dtype parameter)
- Other options:
- read_html(), read_excel(),…
3. Viewing and inspecting data frame properties
4. Selecting columns
5. Descriptive statistics
| Time |
Topic |
| 0:45 |
What is a Data Frame? |
| 3:10 |
Dataframe as a list of lists |
| 5:20 |
Dataframe as a collection of dictionaries |
| 10:20 |
Loading data into a dataframe (read_csv()) |
| 14:30 |
Exploring your data - revealing column data types |
| 16:35 |
Specifying data types when importing with read_csv() |
| 18:06 |
Specifying a column to be the index when importing with read_csv() |
| Time |
Topic |
| 0:20 |
Inspecting the data with head(), tail() and sample() |
| 1:45 |
Reading in raw text files stored on the internet; more on read_csv() |
| 4:45 |
Revealing aspects of your dataframe: len(df), df.shape, df.size |
| 6:42 |
Listing columns of your dataframe with df.columns |
| 8:05 |
Listing the index of your dataframe with df.index |
| 8:55 |
Setting the index column when reading in your data with read_csv() |
| 10:35 |
Listing data frame info with df.info() |
| 13:15 |
Selecting specific columns from your data frame into a new dataframe |
| 16:15 |
Selecting a single column into a Series object; what is a Series object? |
| 17:20 |
Referring to columns: brackets (df['column']) vs dot notation (df.column) |
| 19:21 |
Descriptive statistics for a column of data |
| 20:39 |
Quantiles |
| 21:25 |
Correlations among numeric columns |
| 22:58 |
Styling your correlation output |
| 24:47 |
Generating summary stats with df.describe() |
| 25:25 |
Listing unique values and number of unique values with df.unique() and df.nunique() |
| 26:52 |
Listing number of records for each value with value_counts() |
| 28:12 |
Basic plots in Pandas: histograms with df.hist() |
| 30:32 |
Boxplots |
3. Pandas - Analysis 1