I'm pretty new to Python and I'm having difficulty figuring out how to use the structs. What would the C structs below look like when they are converted into Python?
These are the structs I have:
struct dataT
{
int m;
};
struct stack
{
int top;
struct dataT items[STACKSIZE];
} st;
How would this statement be represented in Python?
st.items[st.top].m
You just need to define your dataT class
class dataT():
def __init__(self, m=0):
self.m = m
You can instantiate one like
d = dataT(5)
The stack behavior you can get from the list class already
>>> l = [dataT(i) for i in range(5)]
>>> l.pop().m
4
>>> l.pop().m
3
>>> l.pop().m
2
>>> l.pop().m
1
>>> l.pop().m
0
>>> l.append(dataT(3))
>>> l.pop().m
3
m will be whatever type you assign to it. I happened to put int values in there, but you can put anything. Python is not a statically-typed language.list (analogous to your stack) is a Python sequence. Meaning it is sortable, indexable, resizeable, sliceable, etc. In that regard it is similar to a std::vector<T> in C++, but it is also heterogeneous. The way to limit the values to int would be to do some kind of validation using isinstance(m, int) or something like that.You can use namedtuples to construct classes that can represent your structs:
from collections import namedtuple
dataT = namedtuple("dataT", ['m'])
stack = namedtuple("stack", ['top', 'items'])
st = stack(0, [])
st.items.append(dataT(5))
st.items[st.top].m
Though you will probably find that the stack class is unnecessary as pointed out list already has this behaviour.
structs and Python namedtuples is that the latter are immutable.
st.top = 1 would update st in place.structs are mutable. namedtuples are not.
structis just aclasswhere all the members and methods arepublicinstead ofprivateby default. In fact in this regard Python's classes are closer to C'sstructthanclasssince there isn't a notion ofprivatestructis simply a class where all the members and methods are public by default. In C,structs can't have methods because they're not classes since there's no such thing. C also doesn't have a concept of public and private.