Python：列表中有多种数据类型

Question

Using: Py3.X

Hi, i have a list as shown below, and i want to print it's field individually, May i know how can i store multiple data types into a variable.

Failed:

S = [1, 2, a, b]

NameError: name 'a' is not defined

Success:

T = ['1','2','a','b']
print(T[1])
2

How to make 'S' into the format of 'T' that every field is saved with single quotes. else how can i use 'S' list without putting those fields under single quotes.

required output:

print(S[1])
2

Answer 1

When we write:

var = 'a'    # This is string 'a'

var will store a reference to the string 'a' .

When we write:

var = a      # This is variable a

var will store a reference which the variable a is storing.

---

You can do something like this:

S = [1, 2, 'a', 'b']    # First two are integers and the last two are strings. 

Answer 2

you either have to define a, or assign it as a string:

a = 3
l = [1,2,a]
print(l)

output:

[1, 2, 3]

OR

l = [1,2,'a']
print(l)

output:

[1, 2, 'a']

your error is because you haven't assigned a value to a