[2/4] mesos git commit: CLI: Added a Table abstraction.

[jo...@apache.org]

CLI: Added a Table abstraction.

This utility class helps print information in left-aligned columns.
This will be used by future plugins.

NOTE: The original review was posted by Kevin Klues on behalf of
Haris Choudhary ( https://reviews.apache.org/r/52948/ ).

Review: https://reviews.apache.org/r/58381/


Project: http://git-wip-us.apache.org/repos/asf/mesos/repo
Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/12e4812e
Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/12e4812e
Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/12e4812e

Branch: refs/heads/master
Commit: 12e4812e360d553539a810512d08bef6434d48af
Parents: 703d001
Author: Haris Choudhary <ha...@gmail.com>
Authored: Thu Apr 13 18:22:01 2017 -0700
Committer: Joseph Wu <jo...@apache.org>
Committed: Thu Apr 13 18:22:40 2017 -0700

----------------------------------------------------------------------
 src/cli_new/lib/cli/util.py | 93 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/mesos/blob/12e4812e/src/cli_new/lib/cli/util.py
----------------------------------------------------------------------
diff --git a/src/cli_new/lib/cli/util.py b/src/cli_new/lib/cli/util.py
index ace07fb..27c4f17 100644
--- a/src/cli_new/lib/cli/util.py
+++ b/src/cli_new/lib/cli/util.py
@@ -21,6 +21,7 @@ A collection of helper functions used by the CLI and its Plugins.
 import imp
 import importlib
 import os
+import re
 import textwrap
 
 from cli.exceptions import CLIException
@@ -149,3 +150,95 @@ def format_subcommands_help(cmd):
             flag_string += "  %s%s%s\n" % (flag, " " * num_spaces, flags[flag])
 
     return (arguments, short_help, long_help, flag_string)
+
+
+class Table(object):
+    """
+    Defines a custom table structure for printing to the terminal.
+    """
+    def __init__(self, columns):
+        """
+        Initialize a table with a list of column names
+        to act as headers for each column in the table.
+        """
+        if not isinstance(columns, list):
+            raise CLIException("Column headers must be supplied as a list")
+
+        for column in columns:
+            if re.search(r"(\s)\1{2,}", column):
+                raise CLIException("Column headers cannot have more"
+                                   " than one space between words")
+
+        self.table = [columns]
+        self.padding = [len(column) for column in columns]
+
+    def __getitem__(self, index):
+        return list(self.table[index])
+
+    def dimensions(self):
+        """
+        Returns the dimensions of the table as (<num-rows>, <num-columns>).
+        """
+        return (len(self.table), len(self.table[0]))
+
+    def add_row(self, row):
+        """
+        Add a row to the table. Input must be a list where each entry
+        corresponds to its respective column in order.
+        """
+        if len(row) != len(self.table[0]):
+            raise CLIException("Number of entries and columns do not match!")
+
+        # Adjust padding for each column.
+        for index, elem in enumerate(row):
+            if len(elem) > self.padding[index]:
+                self.padding[index] = len(elem)
+
+        self.table.append(row)
+
+    def __str__(self):
+        """
+        Convert a table to string for printing.
+        """
+        table_string = ""
+        for r_index, row in enumerate(self.table):
+            for index, entry in enumerate(row):
+                table_string += "%s%s" % \
+                        (entry, " " * (self.padding[index] - len(entry) + 2))
+
+            if r_index != len(self.table) - 1:
+                table_string += "\n"
+
+        return table_string
+
+    @staticmethod
+    def parse(string):
+        """
+        Parse a string previously printed as a `Table` back into a `Table`.
+        """
+        lines = string.split("\n")
+
+        # Find the location and contents of column headers in the string.
+        # Assume only single spaces between words in column headers.
+        matches = re.finditer(r"([\w\d]+\s?[\w\d]+)+", lines[0])
+        columns = [(m.start(), m.group()) for m in matches]
+
+        # Build a table from the column header contents.
+        table = Table([c[1] for c in columns])
+
+        # Fill in the subsequent rows.
+        for line in lines[1:]:
+            row = []
+            start_indices = [c[0] for c in columns]
+
+            for i, start_index in enumerate(start_indices):
+                if i + 1 < len(start_indices):
+                    column = line[start_index:start_indices[i + 1]]
+                else:
+                    column = line[start_index:]
+
+                row.append(str(column.strip()))
+
+            table.add_row(row)
+
+        return table