Files
python_charts/scripts/custom_chart.py
T

89 lines
2.5 KiB
Python

#!/usr/bin/env python3
"""
custom_chart.py
---------------
Plot arbitrary FRED series stored in `data/fred.db`.
Example:
python scripts/custom_chart.py --series UNRATE DCOILWTICO --start 2000-01-01 --end 2020-12-31
"""
from __future__ import annotations
import argparse
from datetime import datetime
from pathlib import Path
from typing import Iterable
import matplotlib.dates as mdates
import matplotlib.pyplot as plt
import pandas as pd
# IMPORTANT: import common directly (no "scripts." prefix)
from scripts.common import fetch_series_db, save_figure
def fetch_series_multi(
series: Iterable[str],
start: datetime,
end: datetime,
db_path: str | Path = Path("data/fred.db"),
) -> pd.DataFrame:
"""Load one or more FRED series from a local SQLite DB."""
return fetch_series_db(series, start, end, db_path)
def plot_series(df: pd.DataFrame) -> plt.Figure:
"""Plot each column of `df` on a shared axis."""
fig, ax = plt.subplots(figsize=(10, 5))
for col in df.columns:
ax.plot(df.index, df[col], label=col)
ax.set_xlabel("Date")
ax.set_ylabel("Value")
ax.legend(frameon=False)
ax.grid(axis="y", linestyle="--", alpha=0.4)
ax.xaxis.set_major_locator(mdates.YearLocator(base=5))
ax.xaxis.set_minor_locator(mdates.YearLocator())
ax.xaxis.set_major_formatter(mdates.DateFormatter("%Y"))
fig.autofmt_xdate()
fig.tight_layout()
return fig
def main(argv: list[str] | None = None) -> plt.Figure:
p = argparse.ArgumentParser(description="Plot FRED series from a local DB")
p.add_argument("--series", nargs="+", required=True, help="FRED series names")
p.add_argument(
"--start", type=str, default="1970-01-01", help="start date YYYY-MM-DD"
)
p.add_argument(
"--end",
type=str,
default=datetime.today().strftime("%Y-%m-%d"),
help="end date YYYY-MM-DD",
)
p.add_argument("--db", type=str, default="data/fred.db", help="path to SQLite DB")
p.add_argument(
"--output",
type=str,
default=None,
help="optional path to save the figure (PNG or PDF)",
)
args = p.parse_args(argv)
start_dt = datetime.fromisoformat(args.start)
end_dt = datetime.fromisoformat(args.end)
data = fetch_series_multi(args.series, start_dt, end_dt, args.db)
fig = plot_series(data)
save_figure(fig, args.output, __file__)
if argv is None:
fig.show()
return fig
if __name__ == "__main__":
main()