Yes, PyCon2005 falls during Holy Week. Fear not, there are some interesting-looking worship possibilities nearby. I'm not a local, it's based totally on websurfing.
Map of places of worship
Their websites (by proximity to Cafritz)
[http://www.gwhillel.org/site/PageServer?pagename=HomePage Hillel](Jewish)
[http://www.stmarysfoggybottom.org/ St. Mary's](Episcopal/ Anglican)
[http://www.westernpresbyterian.org/ Western Presbyterian]
[http://www.theunitedchurch.org/ The United Church](United Church of Christ and United Methodist) (no German services that week - aber schade!)
[http://www.stpauls-kst.com/ St. Paul's](Anglo-Catholic)
[http://www.parishes.org/stephenmartyr.html St. Stephen Martyr](Catholic) (not a reference to the PyCon chair) (I think)
[http://www.stmatthewscathedral.org/ St. Matthew's]
Wednesday worship
6:45 AM: Angelus & Morning Prayer at [http://www.stpauls-kst.com/ St. Paul's]
7 AM: Low Mass at [http://www.stpauls-kst.com/ St. Paul's]
7 AM: Mass at [http://www.stmatthewscathedral.org/ St. Matthew's]
7:30 AM: Morning Prayer at [http://www.stmatthewscathedral.org/ St. Matthew's]
8 AM: Mass at [http://www.stmatthewscathedral.org/ St. Matthew's]
11 AM: Confessions at [http://www.stmatthewscathedral.org/ St. Matthew's]
12 PM: Low Mass at [http://www.stpauls-kst.com/ St. Paul's]
12 PM: Mass at [http://www.stmatthewscathedral.org/ St. Matthew's]
5:30 PM: Devotions at [http://www.stpauls-kst.com/ St. Paul's]
5:30 PM: Mass at [http://www.stmatthewscathedral.org/ St. Matthew's]
5:45 PM: Angelus & Evening Prayer at [http://www.stpauls-kst.com/ St. Paul's]
6 PM: Low Mass at [http://www.stpauls-kst.com/ St. Paul's]
7:30 PM: Tenebrae at [http://www.stmatthewscathedral.org/ St. Matthew's]
8 PM: Tenebrae at [http://www.stpauls-kst.com/ St. Paul's]
Maundy Thursday worship
9 AM: Morning Prayer at [http://www.stpauls-kst.com/ St. Paul's]
9 AM: Morning Prayer at [http://www.stmatthewscathedral.org/ St. Matthew's]
9 AM: Confessions at [http://www.stmatthewscathedral.org/ St. Matthew's]
11 AM: Mass of the Lord's Supper at [http://www.stmatthewscathedral.org/ St. Matthew's]
12 PM: Solemn Mass Lord's Supper at [http://www.stmatthewscathedral.org/ St. Matthew's]
5 PM: Confessions at [http://www.stpauls-kst.com/ St. Paul's]
5:30 PM: Adoration of the Blessed Sacrament at [http://www.stmatthewscathedral.org/ St. Matthew's]
5:45 PM: Evening Prayer at [http://www.stpauls-kst.com/ St. Paul's]
6:30 PM: Mass at [http://www.stpauls-kst.com/ St. Paul's]
9:45 PM: Night Prayer at [http://www.stmatthewscathedral.org/ St. Matthew's]
All Night: Vigil at [http://www.stpauls-kst.com/ St. Paul's]
Good Friday worship
6:30 PM: Solemn Liturgy of the Day at [http://www.stpauls-kst.com/ St. Paul's]
9 AM: Morning Prayer at [http://www.stpauls-kst.com/ St. Paul's]
9 AM: Morning Prayer at [http://www.stmatthewscathedral.org/ St. Matthew's]
11 AM: Confessions at [http://www.stmatthewscathedral.org/ St. Matthew's]
12 PM: Stations of the Cross, with Meditations at [http://www.stpauls-kst.com/ St. Paul's]
12 PM: choral meditations at [http://www.stmatthewscathedral.org/ St. Matthew's]
1 PM: Liturgy of the Lord's Passion at [http://www.stmatthewscathedral.org/ St. Matthew's]
4 PM: Liturgia de la Pasión at [http://www.stmatthewscathedral.org/ St. Matthew's]
5 PM: Confessions at [http://www.stpauls-kst.com/ St. Paul's]
5:45 PM: Evening Prayer at [http://www.stpauls-kst.com/ St. Paul's]
7:30 PM: Stations of the Cross at [http://www.stmatthewscathedral.org/ St. Matthew's]