Python简单程序遍历列表

Question

I'm new to programming and I'm making a simple program to test. Here is the code:

list1 = [1,2,d,,t,h,7,8]

for x in list1:
    if x == 

I'm trying to iterate in my list and check to see which item is a string and which is a number(I know its basic, but im new). So what would be a correct way to write this line of code. All suggestions would help

Answer 1

In Python, use the builtin isinstance(variable, type) to test whether a variable is of a given type.

The type variable can also be a tuple of several types to test against.

Answer 2

Your list is a little messed up. If those letters are supposed to be strings, it should look like this:

list1 = [1,2,'d','t','h',7,8]

Otherwise they are referring to variables.

To check if number

for x in list1:
    if isinstance(x, int):
        ...

To check if string

for x in list1:
    if isinstance(x, str):
       ...

Combination

for x in list1:
    if x.isinstance(x, int):
        ....
    elif isinstance(x, str)L
       ....

Answer 3

This should print the type of each element in your list

for item in list1:
    print type(item)

Answer 4

Assuming your list contains purely numbers and strings:

for x in list1:
    if type(x) == str:
        # do something
    else:
        # do something for numbers

Answer 5

Since everyone is giving answers similar to my old one (see below), I'll try something else.You can easily make 2 lists that separate ints and strings with Python's list comprehensions:

strings = [x for x in list1 if isinstance(x, str)]
intlist = [x for x in list1 if isinstance(x, int)]

Using list comprehensions made the code more compact and easier to understand.

Old response:

list1 = [1, 4, 5, '5', '3', 3, 'a']
for x in list1:
    if(isinstance(x, str)):
        print(str(x) + ' is a string.')
    else:
        print(str(x) + ' is not a string.')

Answer 6

You could try this one,

list1=[1,2,'d','t','h',7,8]

for data in list1:
    if type(data) is str:
        #do something with it
    elif type(data) is int:
        #do something with it

you can try something like this or any of those methods mentioned from other answers in the python interpreter to see it works -

>> type(1) is str

and you would get

>> False