build: scripts to not require electrum to be installed

contrib/build-wine/unsign.sh

@@ -14,7 +14,7 @@ set -e
 mkdir -p signed >/dev/null 2>&1
 mkdir -p signed/stripped >/dev/null 2>&1
 
-version=$(python3 -c "import electrum; print(electrum.version.ELECTRUM_VERSION)")
+version=$("$CONTRIB"/print_electrum_version.py)
 
 echo "Found $(ls dist/*.exe | wc -w) files to verify."
 

contrib/print_electrum_version.py

@@ -0,0 +1,22 @@
+#!/usr/bin/python3
+# For usage in shell, to get the version of electrum, without needing electrum installed.
+# For example:
+# $ VERSION=$("$CONTRIB"/print_electrum_version.py)
+# instead of
+# $ VERSION=$(python3 -c "import electrum; print(electrum.version.ELECTRUM_VERSION)")
+
+import importlib.util
+import os
+
+
+if __name__ == '__main__':
+    project_root = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
+    version_file_path = os.path.join(project_root, "electrum", "version.py")
+
+    # load version.py; needlessly complicated alternative to "imp.load_source":
+    version_spec = importlib.util.spec_from_file_location('version', version_file_path)
+    version_module = version = importlib.util.module_from_spec(version_spec)
+    version_spec.loader.exec_module(version_module)
+
+    print(version.ELECTRUM_VERSION)
+

contrib/release.sh

@@ -79,7 +79,7 @@ if [ ! -z "$RELEASEMANAGER" ] ; then
 fi
 
 
-VERSION=$(python3 -c "import electrum; print(electrum.version.ELECTRUM_VERSION)")
+VERSION=$("$CONTRIB"/print_electrum_version.py)
 info "VERSION: $VERSION"
 REV=$(git describe --tags)
 info "REV: $REV"

contrib/release_www.sh

@@ -34,7 +34,7 @@ if [ -z "$ELECTRUM_SIGNING_WALLET" ] || [ -z "$ELECTRUM_SIGNING_ADDRESS" ]; then
     exit 1
 fi
 
-VERSION=$(python3 -c "import electrum; print(electrum.version.ELECTRUM_VERSION)")
+VERSION=$("$CONTRIB"/print_electrum_version.py)
 info "VERSION: $VERSION"
 
 set -x

contrib/upload.sh

@@ -16,7 +16,7 @@ fi
 
 cd "$PROJECT_ROOT"
 
-VERSION=$(python3 -c "import electrum; print(electrum.version.ELECTRUM_VERSION)")
+VERSION=$("$CONTRIB"/print_electrum_version.py)
 echo "$VERSION"
 
 if [ -z "$ELECBUILD_UPLOADFROM" ]; then