Fix Python module names. (#4473)

In particular, ensure that they are keyword-safe. This affects
`aws:lambda:*` in particular: prior to these changes, we were generating
code into `pulumi_aws.lamdba`, which is not referencable due to its use
of the `lamdba` keyword. With these changes, we generate code into
`pulumi_aws.lambda_`.

There is also a small fix for multi-line non-formatted strings: these
strings do not need escaped braces.

CHANGELOG.md

@@ -16,6 +16,9 @@ CHANGELOG
 - Ensure Go accessor methods correctly support nested fields of optional outputs
   [#4456](https://github.com/pulumi/pulumi/pull/4456)
 
+- Ensure generated Python module names are keyword-safe.
+  [#4473](https://github.com/pulumi/pulumi/pull/4473)
+
 
 ## 2.0.0 (2020-04-16)
 

pkg/codegen/python/gen.go

@@ -1152,7 +1152,7 @@ func GeneratePackage(tool string, pkg *schema.Package, extraFiles map[string][]b
 
 	var getMod func(token string) *modContext
 	getMod = func(token string) *modContext {
-		modName := pkg.TokenToModule(token)
+		modName := PyName(pkg.TokenToModule(token))
 		mod, ok := modules[modName]
 		if !ok {
 			mod = &modContext{

pkg/codegen/python/gen_program.go

@@ -72,7 +72,7 @@ func pyName(pulumiName string, isObjectKey bool) string {
 	if isObjectKey {
 		return fmt.Sprintf("%q", pulumiName)
 	}
-	return PyName(cleanName(pulumiName))
+	return PyName(pulumiName)
 }
 
 // genLeadingTrivia generates the list of leading trivia assicated with a given token.
@@ -167,7 +167,13 @@ func (g *generator) genNode(w io.Writer, n hcl2.Node) {
 func resourceTypeName(r *hcl2.Resource) (string, string, string, hcl.Diagnostics) {
 	// Compute the resource type from the Pulumi type token.
 	pkg, module, member, diagnostics := r.DecomposeToken()
-	return pyName(pkg, false), strings.Replace(module, "/", ".", -1), title(member), diagnostics
+
+	components := strings.Split(module, ".")
+	for i, component := range components {
+		components[i] = PyName(component)
+	}
+
+	return pyName(pkg, false), strings.Join(components, "."), title(member), diagnostics
 }
 
 // makeResourceName returns the expression that should be emitted for a resource's "name" parameter given its base name

pkg/codegen/python/gen_program_expressions.go

@@ -172,9 +172,15 @@ func functionName(tokenArg model.Expression) (string, string, string, hcl.Diagno
 	token := tokenArg.(*model.TemplateExpression).Parts[0].(*model.LiteralValueExpression).Value.AsString()
 	tokenRange := tokenArg.SyntaxNode().Range()
 
-	// Compute the resource type from the Pulumi type token.
+	// Compute the function name from the Pulumi type token.
 	pkg, module, member, diagnostics := hcl2.DecomposeToken(token, tokenRange)
-	return cleanName(pkg), strings.Replace(module, "/", ".", -1), title(member), diagnostics
+
+	components := strings.Split(module, ".")
+	for i, component := range components {
+		components[i] = PyName(component)
+	}
+
+	return cleanName(pkg), strings.Join(components, "."), title(member), diagnostics
 }
 
 var functionImports = map[string]string{
@@ -439,7 +445,7 @@ func (g *generator) GenTemplateExpression(w io.Writer, expr *model.TemplateExpre
 		}
 	}
 
-	prefix, isMultiLine, quotes := "", false, `"`
+	formatted, isMultiLine, quotes := false, false, `"`
 	for i, part := range expr.Parts {
 		if lit, ok := part.(*model.LiteralValueExpression); ok {
 			if !isMultiLine && lit.Type() == model.StringType {
@@ -455,17 +461,21 @@ func (g *generator) GenTemplateExpression(w io.Writer, expr *model.TemplateExpre
 				isMultiLine, quotes = true, `"""`
 			}
 		} else {
-			prefix = "f"
+			formatted = true
 		}
 	}
 
 	b := bufio.NewWriter(w)
 	defer b.Flush()
 
+	prefix := ""
+	if formatted {
+		prefix = "f"
+	}
 	g.Fprintf(b, "%s%s", prefix, quotes)
 	for _, expr := range expr.Parts {
 		if lit, ok := expr.(*model.LiteralValueExpression); ok && lit.Type() == model.StringType {
-			g.genEscapedString(b, lit.Value.AsString(), !isMultiLine, true)
+			g.genEscapedString(b, lit.Value.AsString(), !isMultiLine, formatted)
 		} else {
 			g.Fgenf(b, "{%.v}", expr)
 		}

pkg/codegen/python/python.go

@@ -72,7 +72,7 @@ func PyName(name string) string {
 	var components []string     // The components that will be joined together with underscores
 	var currentComponent []rune // The characters composing the current component being built
 	state := stateFirst
-	for _, char := range name {
+	for _, char := range cleanName(name) {
 		switch state {
 		case stateFirst:
 			if unicode.IsUpper(char) {