Clean up number converter util return type.

Author: mikeckennedy

app/ch10_using_sqlachemy/starter/pypi_org/infrastructure/num_convert.py

@@ -1,5 +1,8 @@
-def try_int(text) -> int:
+from typing import Optional
+
+
+def try_int(text) -> Optional[int]:
     try:
         return int(text)
     except:
-        return 0
+        return None

app/ch11_migrations/starter/pypi_org/infrastructure/num_convert.py

@@ -1,5 +1,8 @@
-def try_int(text) -> int:
+from typing import Optional
+
+
+def try_int(text) -> Optional[int]:
     try:
         return int(text)
     except:
-        return 0
+        return None

app/ch12-forms/final/pypi_org/infrastructure/num_convert.py

@@ -1,4 +1,7 @@
-def try_int(text) -> int:
+from typing import Optional
+
+
+def try_int(text) -> Optional[int]:
     try:
         return int(text)
     except:

app/ch12-forms/starter/pypi_org/infrastructure/num_convert.py

@@ -1,5 +1,8 @@
-def try_int(text) -> int:
+from typing import Optional
+
+
+def try_int(text) -> Optional[int]:
     try:
         return int(text)
     except:
-        return 0
+        return None

app/ch13-validation/final/pypi_org/infrastructure/num_convert.py

@@ -1,5 +1,8 @@
-def try_int(text) -> int:
+from typing import Optional
+
+
+def try_int(text) -> Optional[int]:
     try:
         return int(text)
     except:
-        return 0
+        return None

app/ch13-validation/starter/pypi_org/bin/load_data.py

@@ -339,11 +339,11 @@ def make_version_num(version_text):
         return major, minor, build
 
 
-def try_int(text) -> int:
+def try_int(text) -> Optional[int]:
     try:
         return int(text)
     except:
-        return 0
+        return None
 
 
 def init_db():

app/ch13-validation/starter/pypi_org/infrastructure/num_convert.py

@@ -1,5 +1,8 @@
-def try_int(text) -> int:
+from typing import Optional
+
+
+def try_int(text) -> Optional[int]:
     try:
         return int(text)
     except:
-        return 0
+        return None

app/ch14_testing/final/pypi_org/bin/load_data.py

@@ -339,11 +339,11 @@ def make_version_num(version_text):
         return major, minor, build
 
 
-def try_int(text) -> int:
+def try_int(text) -> Optional[int]:
     try:
         return int(text)
     except:
-        return 0
+        return None
 
 
 def init_db():

app/ch14_testing/final/pypi_org/infrastructure/num_convert.py

@@ -1,5 +1,8 @@
-def try_int(text) -> int:
+from typing import Optional
+
+
+def try_int(text) -> Optional[int]:
     try:
         return int(text)
     except:
-        return 0
+        return None

app/ch14_testing/starter/pypi_org/bin/load_data.py

@@ -339,11 +339,11 @@ def make_version_num(version_text):
         return major, minor, build
 
 
-def try_int(text) -> int:
+def try_int(text) -> Optional[int]:
     try:
         return int(text)
     except:
-        return 0
+        return None
 
 
 def init_db():