Recipes

All examples use the 2010 archive from Getting started, run from inside the unzipped folder.

A whole season in one file

Each event file holds one team's home games. Give all of them at once:

cwevent -Q -y 2010 -n -f 0,2,3,4,10,14,29,34 2010*.EV? > season_2010.csv

2010*.EV? matches the American League (.EVA) and National League (.EVN) files. The header is written once. On a typical machine this takes about 20 seconds for cwevent and about a minute for cwdaily over all 30 teams (see speed).

Home run leaders

cwdaily has one row per player per game, so season totals are sums:

cwdaily -Q -y 2010 -n -f 0,5,19 2010*.EV? > batting.csv

import csv
from collections import Counter

hr = Counter()
with open("batting.csv", newline="") as f:
    for row in csv.DictReader(f):
        hr[row["PLAYER_ID"]] += int(row["B_HR"])

print(hr.most_common(3))

Output:

[('bautj002', 54), ('pujoa001', 42), ('konep001', 39)]

José Bautista's 54 led the majors in 2010. The count matches the official total.

SQL with SQLite (no extra install)

import csv
import sqlite3

con = sqlite3.connect(":memory:")
with open("season_2010.csv", newline="") as f:
    reader = csv.reader(f)
    columns = next(reader)
    con.execute(f"create table ev ({', '.join(columns)})")
    con.executemany(f"insert into ev values ({','.join('?' * len(columns))})", reader)

# strikeouts by pitcher (EVENT_CD 3)
query = "select PIT_ID, count(*) k from ev where EVENT_CD = '3' group by 1 order by k desc limit 3"
print(con.execute(query).fetchall())

Output (Jered Weaver, Felix Hernandez and Tim Lincecum were the 2010 strikeout leaders):

[('weavj003', 233), ('hernf002', 232), ('linct001', 231)]

Values are text; compare with quotes ('3') or cast(... as integer).

pandas or DuckDB

import pandas as pd

events = pd.read_csv("season_2010.csv")

DuckDB reads the file directly: duckdb.sql("select * from 'season_2010.csv' limit 5").

One game, or a range of dates

cwevent -Q -y 2010 -n -f 0,2,29 -i NYA201004130 2010NYA.EVA     # one game
cwevent -Q -y 2010 -n -f 0,2,29 -s 0601 -e 0630 2010NYA.EVA      # June only

Quiet output in scripts

-Q turns off the progress lines Chadwick prints. Send errors to a file with 2> errors.txt so a bad line in an event file does not get lost.