diff --git a/Cargo.toml b/Cargo.toml
index 3c09ade..0a8498c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -29,7 +29,7 @@ md-5 = "0.10.5"
 # bitflags = "1.3.2"
 hex = "0.4.3"
 indexmap = "2.0.0"
-pyo3 = { version = "0.18.1", features = ["extension-module"], optional = true }
+pyo3 = { version = "0.20.0", features = ["extension-module"], optional = true }
 
 [lib]
 name = "rpmrepo_metadata"
diff --git a/src/common.rs b/src/common.rs
index a79f975..8f39c65 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -21,7 +21,7 @@ use std::fmt;
 /// without a caret, e.g. 0.5.0 vs 0.5.0~rc1. Including ^ in a version is used for denoting snapshots
 /// not directly associated with an upstream release and will force it to sort higher, e.g.
 /// 0.5.0 vs 0.5.0^deadbeef
-#[derive(Debug, Eq, Default, Clone)]
+#[derive(Clone, Debug, Default, Eq, Hash)]
 pub struct EVR {
     pub epoch: String,
     pub version: String,
diff --git a/src/metadata.rs b/src/metadata.rs
index acaa5fc..23bf839 100644
--- a/src/metadata.rs
+++ b/src/metadata.rs
@@ -6,6 +6,7 @@
 
 use std::convert::TryInto;
 use std::io::{BufRead, Write};
+use std::hash::{Hash, Hasher};
 use std::os::unix::prelude::MetadataExt;
 use std::path::{Path, PathBuf};
 
@@ -155,7 +156,7 @@ impl TryInto<CompressionType> for &str {
 //     }
 // }
 
-#[derive(Debug, PartialEq, Default)]
+#[derive(Clone, Default, Debug, PartialEq, Hash)]
 pub struct Package {
     // pub(crate) parse_state: ParseState,
     pub name: String,
@@ -576,7 +577,7 @@ impl Package {
     }
 }
 
-#[derive(Debug, PartialEq, Clone, Copy)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum ChecksumType {
     Md5,
     Sha1,
@@ -593,7 +594,7 @@ impl Default for ChecksumType {
     }
 }
 
-#[derive(Debug, PartialEq, Clone)]
+#[derive(Clone, Debug, PartialEq)]
 pub enum Checksum {
     Md5(String),
     Sha1(String),
@@ -611,6 +612,23 @@ impl Default for Checksum {
     }
 }
 
+impl Hash for Checksum {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        match self {
+            Self::Md5(hash) => format!("md5:{}", hash).hash(state),
+            Self::Sha1(hash) => format!("sha1:{}", hash).hash(state),
+            Self::Sha224(hash) => format!("sha224:{}", hash).hash(state),
+            Self::Sha256(hash) => format!("sha256:{}", hash).hash(state),
+            Self::Sha384(hash) => format!("sha384:{}", hash).hash(state),
+            Self::Sha512(hash) => format!("sha512:{}", hash).hash(state),
+            // TODO: adjust this representation. Currently these exist because of reuse of these enums
+            // to represent intermediate parsing states, but those probably ought to be pulled out somehow
+            Self::Unknown(hash) => unimplemented!(),
+            Self::Empty => unimplemented!(),
+        }
+    }
+}
+
 impl Checksum {
     pub fn try_create<N: AsRef<[u8]> + Sized>(
         checksum_type: N,
@@ -719,21 +737,21 @@ impl Checksum {
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Default)]
+#[derive(Clone, Debug, Default, Hash, PartialEq)]
 pub struct Changelog {
     pub author: String,
     pub timestamp: u64,
     pub description: String,
 }
 
-#[derive(Debug, PartialEq, Default)]
+#[derive(Copy, Clone, Debug, Default, Hash, PartialEq)]
 pub struct HeaderRange {
     pub start: u64,
     pub end: u64,
 }
 
 // Requirement (Provides, Conflicts, Obsoletes, Requires).
-#[derive(Clone, Debug, PartialEq, Default)]
+#[derive(Clone, Debug, Default, Hash, PartialEq)]
 pub struct Requirement {
     pub name: String,
     pub flags: Option<String>,
@@ -743,6 +761,7 @@ pub struct Requirement {
     pub preinstall: bool,
 }
 
+#[derive(Copy, Clone, Debug, Hash, PartialEq)]
 pub enum RequirementType {
     LT,
     GT,
@@ -780,7 +799,7 @@ impl TryFrom<&str> for RequirementType {
     }
 }
 
-#[derive(Clone, Copy, Debug, PartialEq)]
+#[derive(Copy, Clone, Debug, PartialEq, Hash)]
 pub enum FileType {
     File,
     Dir,
@@ -814,7 +833,7 @@ impl Default for FileType {
     }
 }
 
-#[derive(Clone, Debug, PartialEq, Default)]
+#[derive(Clone, Debug, Default, Hash, PartialEq)]
 pub struct PackageFile {
     pub filetype: FileType,
     pub path: String,
diff --git a/src/repository.rs b/src/repository.rs
index 8da6e00..3d708fe 100644
--- a/src/repository.rs
+++ b/src/repository.rs
@@ -188,7 +188,7 @@ impl Repository {
 /// - `metadata_compression_type` - The type of compression to use for repository metadata.
 /// - `metadata_checksum_type` - The type of checksums to use for metadata.
 /// - `package_checksum_type` - The type of checksums to use for packages.
-#[derive(Debug, Copy, Clone)]
+#[derive(Copy, Clone, Debug)]
 pub struct RepositoryOptions {
     pub simple_metadata_filenames: bool,
     pub metadata_compression_type: CompressionType,