Python Charts

This initial chart is a self‐contained toolkit that:

• Fetches U.S. unemployment rate (UNRATE) and WTI crude oil price (DCOILWTICO) from FRED :contentReference[oaicite:1]{index=1}
• Stores the series in a local SQLite database (data/fred.db) :contentReference[oaicite:2]{index=2}
• Produces a dual‐axis plot of unemployment vs. lagged oil price, with customizable lag, date range, and styling :contentReference[oaicite:3]{index=3}

Table of Contents

• Quickstart
• Repository Structure
• Usage
• Custom Charts
• Details
• Dependencies
• Troubleshooting
• License

---

🚀 Quickstart

# Clone the repo
git clone https://github.com/your-org/python_charts.git
cd python_charts

# Activate your virtual environment
source venv/bin/activate
# Install dependencies
pip install -r requirements.txt
# Plot the lagged UNRATE vs. Oil chart
./startup.sh lagged_oil_unrate --offset 12 --end 2025-05-31 --extend-years 5

This will:

1. Upgrade pip & setuptools globally

2. Install required packages from requirements.txt via

   pip install --upgrade -r requirements.txt
   

3. Download UNRATE & DCOILWTICO into data/fred.db if missing ([Stack Overflow][3], [martinheinz.dev][4])

4. Generate the chart with a 12‐month oil lead, extending the x‐axis by 5 years ([martinheinz.dev][4], [Real Python][1])

---

📁 Repository Structure

python_charts/
├── data/
│   └── fred.db                            # Local FRED snapshot (SQLite)
├── scripts/
│   ├── __init__.py                        # Marks this folder as a Python package
│   ├── common.py                          # Data‐loading, validation, and save_figure utils
│   ├── refresh_data.py                    # Downloads and stores FRED series
│   ├── lagged_oil_unrate_chart_styled.py  # Offline plot of UNRATE vs. WTI oil with lag
│   ├── bitcoin_m2_chart.py                # Plot Bitcoin vs. Global M2 overlay
│   └── custom_chart.py                    # Generic plotting for arbitrary FRED series
├── outputs/                               # Generated chart files (PNGs)
├── Makefile                               # High‐level targets (install, data, plot, etc.)
├── startup.sh                             # Installs dependencies, ensures data, runs commands
├── requirements.txt                       # Python dependencies
└── README.md                              # This file

Note: An empty scripts/__init__.py file has been added so that Python treats scripts/ as a package. Because of this, each script can import common.py via:

from common import fetch_series_db, save_figure, validate_dataframe, validate_overlap

rather than from scripts.common import …. ([Real Python][1], [Software Engineering Stack Exchange][2])

---

⚙️ Usage

1. Refresh FRED Data

To refresh (or initially populate) the SQLite database with FRED series, run:

# Either let startup.sh dispatch via alias:
./startup.sh refresh_data --series UNRATE CPIAUCSL --start 1960-01-01 --output outputs/chart.png

# Or invoke it directly as a module (dependencies must already be installed):
python -m scripts.refresh_data --series UNRATE CPIAUCSL --start 1960-01-01 --output outputs/chart.png

This command:

• Connects to FRED via pandas_datareader
• Downloads the specified series (e.g., UNRATE and CPIAUCSL) from the start date through today
• Writes each series to its own table in data/fred.db
• Saves a PNG of any default plot (if --output is provided) to outputs/ ([Stack Overflow][3], [GitHub][5])

refresh_data.py options

Option	Description
--series	One or more FRED series names (e.g., UNRATE, DCOILWTICO)
--start	Start date in YYYY-MM-DD format
--end	End date in YYYY-MM-DD format (defaults to today)

Example:

# Populate fred.db with four series (UNRATE, WTI, Bitcoin, and Global M2)
./startup.sh refresh_data --series UNRATE DCOILWTICO CBBTCUSD GLOBAL_M2 --start 1973-01-01

---

2. Generate the Default UNRATE vs. Oil Chart

Once data is present, generate the dual‐axis plot of UNRATE vs. lagged WTI oil price:

# Default: 18‐month lag, default date range (1973‐01‐01 to today), and 3‐year extension
./startup.sh lagged_oil_unrate --offset 18

What happens under the hood:

1. startup.sh sees --offset 18 and forwards it to the default module scripts.lagged_oil_unrate_chart_styled as:

   python -m scripts.lagged_oil_unrate_chart_styled --offset 18
   

2. The script imports UNRATE and DCOILWTICO from fred.db via:

   from common import fetch_series_db, save_figure, validate_dataframe, validate_overlap
   

   ([Real Python][1], [Software Engineering Stack Exchange][2])

3. Converts both series to month‐end indices, resamples oil to a monthly average, and aligns their date ranges.

4. Validates that neither series is empty, contains NaN, or has no overlap (raising a ValueError if any issue).

5. Applies the specified lag (e.g., 18 months), then plots UNRATE on the left y‐axis and log‐scaled WTI on the right y‐axis.

6. Saves the figure to outputs/lagged_oil_unrate_chart_styled_<timestamp>.png (unless --output is specified). ([martinheinz.dev][4], [Real Python][1])

Customizing the UNRATE vs. Oil Chart

# 6‐month lag, start in 1980, end in 2025‐05‐31, extend by 2 years
./startup.sh lagged_oil_unrate --offset 6 --start 1980-01-01 --end 2025-05-31 --extend-years 2

Option	Description
--offset	Lag in months (positive means oil is shifted forward relative to UNRATE)
--start	Start date for both series (YYYY-MM-DD)
--end	End date for both series (YYYY-MM-DD)
--extend-years	Number of years to extend the x‐axis beyond the end date
--output	Save the figure to this path (PNG or PDF)

Note: If you do not specify --output, save_figure(...) creates a timestamped PNG in outputs/ by default: outputs/lagged_oil_unrate_chart_styled_20250531_121045.png ([Python Packaging][6], [Real Python][1])

---

Custom Charts

You can plot any combination of FRED series stored in data/fred.db using scripts/custom_chart.py. Each column in the DataFrame is plotted on a shared axis.

# Either let startup.sh dispatch via alias:
./startup.sh custom_chart --series UNRATE DCOILWTICO --start 2000-01-01 --end 2020-12-31

# Or invoke it directly as a module (dependencies must already be installed):
python -m scripts.custom_chart --series UNRATE DCOILWTICO --start 2000-01-01 --end 2020-12-31

• Internally, custom_chart.py invokes:

  from common import fetch_series_db, save_figure
  

  to load the requested series and save the figure.

• The same invocation is available via Make:

  make plot-custom ARGS="--series UNRATE DCOILWTICO --start 2000-01-01 --end 2020-12-31"
  ``` :contentReference[oaicite:12]{index=12}  
  

---

Bitcoin vs. Global M2

Before running bitcoin_m2_chart.py, make sure the Bitcoin price (CBBTCUSD) and global M2 (GLOBAL_M2) series exist in data/fred.db. If the database is missing these tables, fetch them with refresh_data.py:

# Either let startup.sh dispatch via alias:
./startup.sh refresh_data --series CBBTCUSD GLOBAL_M2 --start 2010-01-01

# Or invoke it directly as a module (dependencies must already be installed):
python -m scripts.refresh_data --series CBBTCUSD GLOBAL_M2 --start 2010-01-01

Once the data is present, generate the Bitcoin‐Global M2 overlay chart:

# Either let startup.sh dispatch via alias:
./startup.sh bitcoin_m2 --btc-series CBBTCUSD --m2-series GLOBAL_M2 --output outputs/chart.png

# Or invoke it directly as a module (dependencies must already be installed):
python -m scripts.bitcoin_m2_chart --btc-series CBBTCUSD --m2-series GLOBAL_M2 --output outputs/chart.png

• This script:

  1. Imports both series from fred.db with:

     from common import fetch_series_db, save_figure
     

     ([Real Python][1], [Software Engineering Stack Exchange][2])

  2. Renames each column to "value" for consistency.

  3. Finds the overlapping date range, shifts M2 by --offset (default = 94 days), and overlays the two series on dual axes.

  4. Saves the figure—e.g., outputs/bitcoin_m2_chart_20250531_090608.png ([martinheinz.dev][4], [Real Python][1])

CLI Options for bitcoin_m2_chart.py:

Option	Default	Description
--btc-series	CBBTCUSD	FRED series code for Bitcoin price
--m2-series	GLOBAL_M2	FRED series code for global M2 money supply
--start	2010-01-01	Start date for fetching both series
--end	Today	End date for fetching both series
--offset	94	Shift M2 by this many days (positive → M2 leads)
--extend-years	1	Years beyond end to extend the x‐axis
--output	None	Optional path to save the figure (PNG/PDF)

---

📝 Details

• Data storage:

  • data/fred.db (SQLite) contains one table per FRED series—each table has columns date (as the index) and <SERIES_NAME> for the value ([Stack Overflow][3], [martinheinz.dev][4]).

• Plot styling:

  • Lagged oil vs. UNRATE chart:

    • Left y‐axis: Unemployment rate (%) from 3% to 15%, with tick marks every 2%
    • Right y‐axis: WTI oil price (USD) on a log scale; ticks double starting at $3 (i.e., 3, 6, 12, 24, etc.) ([martinheinz.dev][4], [Real Python][1])
    • X‐axis: Major tick every 5 years, minor tick every year; format ticks as %Y (e.g., 1980, 1985, 1990) ([Real Python][1], [martinheinz.dev][4])

  • Bitcoin vs. Global M2 chart:

    • Left y‐axis: Bitcoin price (USD) as a linear scale
    • Right y‐axis: Global M2 (billions of USD) as a linear scale
    • X‐axis: Same date formatting as above (major = every 5 years, minor = yearly) ([Real Python][1], [martinheinz.dev][4])

• Utility functions in common.py:

  • fetch_series_db(series_list, start, end, db_path)

    • Opens data/fred.db, reads each series table, slices by date range, and concatenates into a single DataFrame, sorted by date. Raises FileNotFoundError if fred.db is missing. ([Stack Overflow][3], [martinheinz.dev][4])

  • validate_dataframe(df, name)

    • Confirms the DataFrame is nonempty, has a "value" column, contains no nulls, and uses a DatetimeIndex. Raises ValueError otherwise. ([devgem.io][7], [Real Python][1])

  • validate_overlap(df1, df2)

    • Checks for a nonempty overlap in dates between two series; raises ValueError if there is no intersection. ([devgem.io][7], [Real Python][1])

  • save_figure(fig, output, script_path)

    • Saves the Matplotlib Figure to either the given output path or outputs/<script>_<timestamp>.png. ([Python Packaging][6], [Real Python][1])

---

📦 Dependencies

All Python dependencies are listed in requirements.txt and are installed by ./startup.sh:

pandas>=1.5.0
pandas_datareader>=0.10.0
matplotlib>=3.5.0
lxml>=4.6.0
python-dateutil>=2.8.1

Tip: If you run into ModuleNotFoundError: distutils, resolve it by upgrading setuptools:

pip install --upgrade setuptools
``` :contentReference[oaicite:23]{index=23}  

---

🛡️ Troubleshooting

• ModuleNotFoundError: scripts.common not found

  • Ensure you have added scripts/__init__.py and that all from scripts.common import … lines have been updated to from common import …. Then rerun:

    # Run the default lagged-oil chart via startup.sh
    ./startup.sh lagged_oil_unrate --offset 18
    

    or, if you prefer the module form:

    python -m scripts.lagged_oil_unrate_chart_styled --offset 18
    

• ValueError: UNRATE contains null values

  • This indicates that the UNRATE DataFrame has missing (NaN) entries. Possible fixes:

    1. Drop nulls within SQL—e.g., run refresh_data.py --end using the last fully published month rather than “today” ([devgem.io][7], [pyOpenSci][8])
    2. Forward‐fill or backward‐fill missing UNRATE values in common.py before validation (if appropriate) ([pyOpenSci][8], [Real Python][1])
    3. Comment out the strict null check in validate_dataframe(...) (not recommended for publication‐quality charts) ([devgem.io][7], [Real Python][1])

• Database not found

  • If data/fred.db does not exist (e.g., fresh clone), run:

    # Using startup.sh to run via alias
    ./startup.sh refresh_data --series UNRATE DCOILWTICO
    
    # Or run it as a module directly
    python -m scripts.refresh_data --series UNRATE DCOILWTICO
    ``` :contentReference[oaicite:28]{index=28}  
    
    

• Permission errors

  • Ensure you have write access to the project directory, especially for data/ and outputs/. ([Real Python][1], [Roy's Blog][9])

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📄 License

Released under the MIT License. See LICENSE for details. ([Roy's Blog][9], [Real Python][1])