Currently I have data in the following format
A
A -> B -> C -> D -> Z
A -> B -> O
A -> X
This is stored in a list [line1,line2, and so forth]
Now I want to print this in the following manner
A
|- X
|- B
|- O
|- C
|- D
|- Z
I'm new to python so. I was thinking of finding '->' in each element in array and replacing with space. I don't know to go forward.
Here is a little code to get you started (add your own beautifications as needed):
>>> def make_links(data):
'Create a dictionary mapping nodes to a set of their successors'
links = {}
for row in data:
nodes = row.replace(' ', '').split('->')
for a, b in zip(nodes[:-1], nodes[1:]):
links.setdefault(a, set()).add(b)
return links
>>> def draw_tree(links, start, depth=0):
'Recursively print a tree from a given starting point and given depth'
print(' ' * depth + start)
for node in sorted(links.get(start, [])):
draw_tree(links, node, depth+1)
>>> data = ['A', 'A -> B -> C -> D -> Z', 'A -> B -> O', 'A -> X']
>>> links = make_links(data)
>>> links
{'A': {'X', 'B'}, 'C': {'D'}, 'B': {'C', 'O'}, 'D': {'Z'}}
>>> draw_tree(links, start='A')
A
B
C
D
Z
O
X
First we parse the string:
data = """A
A -> B -> C -> D -> Z
A -> B -> O
A -> X
"""
lines = [x.split(' -> ') for x in data.split('\n') if x]
This will return
[['A'], ['A', 'B', 'C', 'D', 'Z'], ['A', 'B', 'O'], ['A', 'X']]
Then we build it:
def addone(owner, data):
o = owner.setdefault(data.pop(0), {})
if data:
addone(o, data)
root = {}
for line in lines:
addone(root, line)
Now the root will be:
{'A': {'X': {}, 'B': {'C': {'D': {'Z': {}}}, 'O': {}}}}
Finally we display it:
def show(base, data):
while data:
k, v = data.pop(0)
print '%s|-%s' % (base, k)
if v:
if data:
show(base + '| ', v.items())
else:
show(base + ' ', v.items())
show("", root.items())
It will output on my place like this:
|-A
|-X
|-B
|-C
| |-D
| |-Z
|-O
O and C has different order, because python dict not remember order, which is easy to change by sort or use collections.OrderedDict
['A', 'A -> B -> C -> D -> Z', 'A -> B -> O', 'A -> X']?