Add advent code for 2020 days 1-4

day_4/part_1.py

@@ -0,0 +1,25 @@
+with open("input") as f:
+	data = [x.replace("\n", " ") for x in f.read().split("\n\n")]
+
+# The fields that passports have, if True, it's required, if False, it's an
+# optional field
+fields = {
+	"byr": True,
+	"iyr": True,
+	"eyr": True,
+	"hgt": True,
+	"hcl": True,
+	"ecl": True,
+	"pid": True,
+	"cid": False
+}
+
+valid_passports = len(data)
+
+for passport in data:
+	for field, required in fields.items():
+		if field not in passport and required:
+			valid_passports -= 1
+			break
+
+print(f"Valid Passports: {valid_passports}")