Learning Data Mining with Python

Chapter 12
We set a test filename so we can see this in action:
import os
filename = os.path.join(os.path.expanduser("~"), "Data", "blogs",
"1005545.male.25.Engineering.Sagittarius.xml")
First, we create a list that will let us store each of the posts:
all_posts = []
Then, we open the file to read:
with open(filename) as inf:
We then set a flag indicating whether we are currently in a post. We will set this to
True when we find a tag indicating the start of a post and set it to False
when we find the closing tag;
post_start = False
We then create a list that stores the current post's lines:
post = []
We then iterate over each line of the file and remove white space:
for line in inf:
line = line.strip()
As stated before, if we find the opening tag, we indicate that we are in a new
post. Likewise, with the close tag:
if line == "":
post_start = True
elif line == "":
post_start = False
When we do find the closing tag, we also then record the full post that we
have found so far. We also then start a new "current" post. This code is on the same
indentation level as the previous line:
all_posts.append("\n".join(post))
post = []
Finally, when the line isn't a start of end tag, but we are in a post, we add the text of
the current line to our current post:
elif post_start:
post.append(line)
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