我有以下文件 <SafeAreaView style ={styles.container}>
<Text style ={styles.title}>New Hot Tokens</Text>
<FlatList
data={listItems}
renderItem={({item}) => <Text style={styles.item}
onPress={() => {
navigation.navigate('Details', {coinID: (item)
});
}}
>{`${item.key}`}</Text>}/>
</SafeAreaView>
);
}
function DetailsScreen({route, navigation}) {
const { coinID } = route.params;
console.log(coinID.key)
const { loading: coinLoading, error, data: coinData } = useQuery(COIN_INFO, {
variables: {
coinForQuery: coinID.key},
pollInterval: 15000,
fetchPolicy: 'network-only',
notifyOnNetworkStatusChange: true
}
);
：
t.py，哪个类型检查正常：
from typing import overload, TypeVar, List, Any, Iterable
class Animal: ...
class Dog(Animal): ...
T = TypeVar('T', bound=Animal)
def foo(self: T) -> T:
return self
但是，如果我将其更改为：
$ mypy t.py
Success: no issues found in 1 source file
(venv) marco@marco-Predator-PH315-52:~/tmp$
然后我收到一个输入错误：
from typing import overload, TypeVar, List, Any, Iterable
class Animal: ...
class Dog(Animal): ...
T = TypeVar('T', bound=Animal)
def foo(self: T) -> T:
if isinstance(self, Dog):
return self
else:
return self
为什么会这样，如果我有一个 $ mypy t.py
t.py:10: error: Incompatible return value type (got "Dog", expected "T")
Found 1 error in 1 file (checked 1 source file)
块，我怎样才能使它类型检查正常？