subtree.py

t1 = {
    "value": 1,
    "children": [
        {
            "value": 2,
            "children": [
                {"value": 3},
                {"value": 4}
            ]
        },
        {
            "value": 5,
            "children": [
                {"value": 6},
                {"value": 7}
            ]
        }
    ]
}

t2 = {
    "value": 5,
    "children": [
        {"value": 6},
        {"value": 7}
    ]
}

def match(t1, t2):
    """Returns True if t1 matches t2, False otherwise."""
    if t1["value"] != t2["value"]:
        return False
    t1_children = t1.get("children", [])
    t2_children = t2.get("children", [])
    if not t1_children and not t2_children:
        return True
    lmatch = match(t1_children[0], t2_children[0])
    rmatch = match(t1_children[1], t2_children[1])
    return lmatch and rmatch

def issubtree(t1, t2):
    """Returns True if t2 is a subtree of t1, False otherwise."""
    if t1["value"] != t2["value"]:  # no match, continue searching t1's nodes
        t1_children = t1.get("children", [])
        if t1_children:
            lmatch = issubtree(t1_children[0], t2)
            rmatch = issubtree(t1_children[1], t2)
            return lmatch or rmatch
        return False
    else: # match, compare the rest of the nodes
        return match(t1, t2)

print(issubtree(t1, t2))