chore: rewrite user-facing messages in Selling module

Conservative cleanup of frappe.throw/msgprint messages per the message style
guide; meaning, severity, and .format() arguments are unchanged:

- index bare {} placeholders as {0}/{1}/... so translators can reorder
- move f-strings / .format() / concatenation out of _() (they break gettext
  extraction and never translate)
- wrap translatable dynamic values (DocType/Select labels) in _()
- fix grammar and colloquialisms
- drop no-op _() wrapping runtime-built strings

Part of #53976.

erpnext/selling/doctype/customer/customer.py

@@ -158,7 +158,7 @@ class Customer(TransactionBase):
 			new_customer_name = f"{self.customer_name} - {cstr(count)}"
 
 			msgprint(
-				_("Changed customer name to '{}' as '{}' already exists.").format(
+				_("Changed customer name to '{0}' as '{1}' already exists.").format(
 					new_customer_name, self.customer_name
 				),
 				title=_("Note"),
@@ -356,7 +356,7 @@ class Customer(TransactionBase):
 		if frappe.db.exists("Customer Group", self.name):
 			frappe.throw(
 				_(
-					"A Customer Group exists with same name please change the Customer name or rename the Customer Group"
+					"A Customer Group exists with the same name. Please change the Customer name or rename the Customer Group"
 				),
 				frappe.NameError,
 			)
@@ -406,7 +406,7 @@ class Customer(TransactionBase):
 			if flt(limit.credit_limit) < outstanding_amt:
 				frappe.throw(
 					_(
-						"""New credit limit is less than current outstanding amount for the customer. Credit limit has to be atleast {0}"""
+						"""New credit limit is less than current outstanding amount for the customer. Credit limit has to be at least {0}"""
 					).format(outstanding_amt)
 				)
 
@@ -440,7 +440,7 @@ class Customer(TransactionBase):
 			self.loyalty_program = loyalty_program[0]
 		else:
 			frappe.msgprint(
-				_("Multiple Loyalty Programs found for Customer {}. Please select manually.").format(
+				_("Multiple Loyalty Programs found for Customer {0}. Please select manually.").format(
 					frappe.bold(self.customer_name)
 				)
 			)

erpnext/selling/doctype/customer/mapper.py

@@ -172,7 +172,7 @@ def make_address(args, is_primary_address=1, is_shipping_address=1):
 	if reqd_fields:
 		msg = _("Following fields are mandatory to create address:")
 		frappe.throw(
-			"{} <br><br> <ul>{}</ul>".format(msg, "\n".join(reqd_fields)),
+			msg + " <br><br> <ul>{}</ul>".format("\n".join(reqd_fields)),
 			title=_("Missing Values Required"),
 		)
 

erpnext/selling/doctype/party_specific_item/party_specific_item.py

@@ -32,4 +32,6 @@ class PartySpecificItem(Document):
 			},
 		)
 		if exists:
-			frappe.throw(_("This item filter has already been applied for the {0}").format(self.party_type))
+			frappe.throw(
+				_("This item filter has already been applied for the {0}").format(_(self.party_type))
+			)

erpnext/selling/doctype/product_bundle/product_bundle.py

@@ -118,9 +118,9 @@ class ProductBundle(Document):
 
 		if len(invoice_links):
 			frappe.throw(
-				"This Product Bundle is linked with {}. You will have to cancel these documents in order to delete this Product Bundle".format(
-					", ".join(invoice_links)
-				),
+				_(
+					"This Product Bundle is linked with {0}. You will have to cancel these documents in order to delete this Product Bundle"
+				).format(", ".join(invoice_links)),
 				title=_("Not Allowed"),
 			)
 

erpnext/selling/page/sales_funnel/sales_funnel.py

@@ -16,7 +16,7 @@ def validate_filters(from_date, to_date, company):
 		frappe.throw(_("To Date must be greater than From Date"))
 
 	if not company:
-		frappe.throw(_("Please Select a Company"))
+		frappe.throw(_("Please select a Company"))
 
 
 @frappe.whitelist()

erpnext/selling/report/sales_partner_commission_summary/sales_partner_commission_summary.py

@@ -47,7 +47,7 @@ class SalesPartnerSummaryReport:
 			frappe.throw(_("Please select the document type first."))
 
 		if self.filters.get("doctype") not in SALES_TRANSACTION_DOCTYPES:
-			frappe.throw(_("DocType can be one of them {0}").format(comma_or(SALES_TRANSACTION_DOCTYPES)))
+			frappe.throw(_("DocType can be one of {0}").format(comma_or(SALES_TRANSACTION_DOCTYPES)))
 
 		if not self.filters.get("company"):
 			frappe.throw(_("Please select a company."))

erpnext/selling/report/sales_partner_commission_summary/test_sales_partner_commission_summary.py

@@ -19,7 +19,7 @@ class SalesPartnerSummaryReportTestMixin(ERPNextTestSuite):
 
 		with self.assertRaisesRegex(
 			frappe.ValidationError,
-			_("DocType can be one of them {0}").format(comma_or(SALES_TRANSACTION_DOCTYPES)),
+			_("DocType can be one of {0}").format(comma_or(SALES_TRANSACTION_DOCTYPES)),
 		):
 			run(self.report_name, self.filters)