ZOOKEEPER-3771: Update zk-merge-pr script to Python3

eolivelli generally I use `2to3` util and check the codepath that I can arrive, manually fix some lines.

But it seems we can verify this patch totally when merging this patch :)

Author: tison <wander4096@gmail.com>

Reviewers: Enrico Olivelli <eolivelli@apache.org>, Norbert Kalmar <nkalmar@apache.org>

Closes apache#1295 from TisonKun/patch-1

zk-merge-pr.py

@@ -32,7 +32,7 @@
 import re
 import subprocess
 import sys
-import urllib2
+import urllib.request, urllib.error, urllib.parse
 import getpass
 
 try:
@@ -75,48 +75,48 @@
 
 def get_json(url):
     try:
-        request = urllib2.Request(url)
+        request = urllib.request.Request(url)
         if GITHUB_OAUTH_KEY:
             request.add_header('Authorization', 'token %s' % GITHUB_OAUTH_KEY)
-        return json.load(urllib2.urlopen(request))
-    except urllib2.HTTPError as e:
+        return json.load(urllib.request.urlopen(request))
+    except urllib.error.HTTPError as e:
         if "X-RateLimit-Remaining" in e.headers and e.headers["X-RateLimit-Remaining"] == '0':
-            print "Exceeded the GitHub API rate limit; see the instructions in " + \
+            print("Exceeded the GitHub API rate limit; see the instructions in " + \
                   "zk-merge-pr.py to configure an OAuth token for making authenticated " + \
-                  "GitHub requests."
+                  "GitHub requests.")
         else:
-            print "Unable to fetch URL, exiting: %s" % url
+            print("Unable to fetch URL, exiting: %s" % url)
         sys.exit(-1)
 
 
 def fail(msg):
-    print msg
+    print(msg)
     clean_up()
     sys.exit(-1)
 
 
 def run_cmd(cmd):
-    print cmd
+    print(cmd)
     if isinstance(cmd, list):
-        return subprocess.check_output(cmd)
+        return subprocess.check_output(cmd, encoding='utf8')
     else:
-        return subprocess.check_output(cmd.split(" "))
+        return subprocess.check_output(cmd.split(" "), encoding='utf8')
 
 
 def continue_maybe(prompt):
-    result = raw_input("\n%s (y/n): " % prompt)
+    result = input("\n%s (y/n): " % prompt)
     if result.lower().strip() != "y":
         fail("Okay, exiting")
 
 def clean_up():
     if original_head != get_current_branch():
-        print "Restoring head pointer to %s" % original_head
+        print("Restoring head pointer to %s" % original_head)
         run_cmd("git checkout %s" % original_head)
 
     branches = run_cmd("git branch").replace(" ", "").split("\n")
 
-    for branch in filter(lambda x: x.startswith(TEMP_BRANCH_PREFIX), branches):
-        print "Deleting local branch %s" % branch
+    for branch in [x for x in branches if x.startswith(TEMP_BRANCH_PREFIX)]:
+        print("Deleting local branch %s" % branch)
         run_cmd("git branch -D %s" % branch)
 
 def get_current_branch():
@@ -144,20 +144,20 @@ def merge_pr(pr_num, target_ref, title, body, pr_repo_desc):
                              '--pretty=format:%an <%ae>']).split("\n")
     distinct_authors = sorted(set(commit_authors),
                               key=lambda x: commit_authors.count(x), reverse=True)
-    primary_author = raw_input(
+    primary_author = input(
         "Enter primary author in the format of \"name <email>\" [%s]: " %
         distinct_authors[0])
     if primary_author == "":
         primary_author = distinct_authors[0]
 
-    reviewers = raw_input(
+    reviewers = input(
         "Enter reviewers in the format of \"name1 <email1>, name2 <email2>\": ").strip()
 
     commits = run_cmd(['git', 'log', 'HEAD..%s' % pr_branch_name,
                       '--pretty=format:%h [%an] %s']).split("\n")
 
     if len(commits) > 1:
-        result = raw_input("List pull request commits in squashed commit message? (y/n): ")
+        result = input("List pull request commits in squashed commit message? (y/n): ")
         if result.lower().strip() == "y":
           should_list_commits = True
         else:
@@ -209,13 +209,13 @@ def merge_pr(pr_num, target_ref, title, body, pr_repo_desc):
 
     merge_hash = run_cmd("git rev-parse %s" % target_branch_name)[:8]
     clean_up()
-    print("Pull request #%s merged!" % pr_num)
-    print("Merge hash: %s" % merge_hash)
+    print(("Pull request #%s merged!" % pr_num))
+    print(("Merge hash: %s" % merge_hash))
     return merge_hash
 
 
 def cherry_pick(pr_num, merge_hash, default_branch):
-    pick_ref = raw_input("Enter a branch name [%s]: " % default_branch)
+    pick_ref = input("Enter a branch name [%s]: " % default_branch)
     if pick_ref == "":
         pick_ref = default_branch
 
@@ -244,21 +244,21 @@ def cherry_pick(pr_num, merge_hash, default_branch):
     pick_hash = run_cmd("git rev-parse %s" % pick_branch_name)[:8]
     clean_up()
 
-    print("Pull request #%s picked into %s!" % (pr_num, pick_ref))
-    print("Pick hash: %s" % pick_hash)
+    print(("Pull request #%s picked into %s!" % (pr_num, pick_ref)))
+    print(("Pick hash: %s" % pick_hash))
     return pick_ref
 
 
 def fix_version_from_branch(branch, versions):
     # Note: Assumes this is a sorted (newest->oldest) list of un-released versions
     if branch == DEV_BRANCH_NAME:
-        versions = filter(lambda x: x == DEFAULT_FIX_VERSION, versions)
+        versions = [x for x in versions if x == DEFAULT_FIX_VERSION]
         if len(versions) > 0:
             return versions[0]
         else:
             return None
     else:
-        versions = filter(lambda x: x.startswith(branch), versions)
+        versions = [x for x in versions if x.startswith(branch)]
         if len(versions) > 0:
             return versions[-1]
         else:
@@ -269,7 +269,7 @@ def resolve_jira_issue(merge_branches, comment, default_jira_id=""):
     asf_jira = jira.client.JIRA({'server': JIRA_API_BASE},
                                 basic_auth=(JIRA_USERNAME, JIRA_PASSWORD))
 
-    jira_id = raw_input("Enter a JIRA id [%s]: " % default_jira_id)
+    jira_id = input("Enter a JIRA id [%s]: " % default_jira_id)
     if jira_id == "":
         jira_id = default_jira_id
 
@@ -288,36 +288,36 @@ def resolve_jira_issue(merge_branches, comment, default_jira_id=""):
 
     if cur_status == "Resolved" or cur_status == "Closed":
         fail("JIRA issue %s already has status '%s'" % (jira_id, cur_status))
-    print ("=== JIRA %s ===" % jira_id)
-    print ("summary\t\t%s\nassignee\t%s\nstatus\t\t%s\nurl\t\t%s/%s\n" % (
-        cur_summary, cur_assignee, cur_status, JIRA_BASE, jira_id))
+    print(("=== JIRA %s ===" % jira_id))
+    print(("summary\t\t%s\nassignee\t%s\nstatus\t\t%s\nurl\t\t%s/%s\n" % (
+        cur_summary, cur_assignee, cur_status, JIRA_BASE, jira_id)))
 
     versions = asf_jira.project_versions(CAPITALIZED_PROJECT_NAME)
     versions = sorted(versions, key=lambda x: x.name, reverse=True)
-    versions = filter(lambda x: x.raw['released'] is False, versions)
+    versions = [x for x in versions if x.raw['released'] is False]
 
-    version_names = map(lambda x: x.name, versions)
-    default_fix_versions = map(lambda x: fix_version_from_branch(x, version_names), merge_branches)
-    default_fix_versions = filter(lambda x: x != None, default_fix_versions)
+    version_names = [x.name for x in versions]
+    default_fix_versions = [fix_version_from_branch(x, version_names) for x in merge_branches]
+    default_fix_versions = [x for x in default_fix_versions if x != None]
     default_fix_versions = ",".join(default_fix_versions)
 
-    fix_versions = raw_input("Enter comma-separated fix version(s) [%s]: " % default_fix_versions)
+    fix_versions = input("Enter comma-separated fix version(s) [%s]: " % default_fix_versions)
     if fix_versions == "":
         fix_versions = default_fix_versions
     fix_versions = fix_versions.replace(" ", "").split(",")
 
     def get_version_json(version_str):
         return filter(lambda v: v.name == version_str, versions)[0].raw
 
-    jira_fix_versions = map(lambda v: get_version_json(v), fix_versions)
+    jira_fix_versions = [get_version_json(v) for v in fix_versions]
 
     resolve = filter(lambda a: a['name'] == "Resolve Issue", asf_jira.transitions(jira_id))[0]
     resolution = filter(lambda r: r.raw['name'] == "Fixed", asf_jira.resolutions())[0]
     asf_jira.transition_issue(
         jira_id, resolve["id"], fixVersions = jira_fix_versions,
         comment = comment, resolution = {'id': resolution.raw['id']})
 
-    print "Successfully resolved %s with fixVersions=%s!" % (jira_id, fix_versions)
+    print("Successfully resolved %s with fixVersions=%s!" % (jira_id, fix_versions))
 
 
 def resolve_jira_issues(title, merge_branches, comment):
@@ -401,7 +401,7 @@ def check_git_remote():
 
     # check if all remote endpoints' URLs point to project git repo
     name = PROJECT_NAME + ".git"
-    for url in repos.values():
+    for url in list(repos.values()):
         if not url.endswith(name):
             fail("Error: not a %s git repo or at least one remote is invalid" % PROJECT_NAME)
 
@@ -419,7 +419,7 @@ def check_jira_env():
     if JIRA_IMPORTED:
 
        if JIRA_USERNAME.strip() != "" and JIRA_PASSWORD.strip() == "":
-           inform_pwd = raw_input("JIRA_USERNAME set but JIRA_PASSWORD is not. Want to inform it? ")
+           inform_pwd = input("JIRA_USERNAME set but JIRA_PASSWORD is not. Want to inform it? ")
            if inform_pwd.strip() == "y":
                JIRA_PASSWORD = getpass.getpass('JIRA PASSWORD: ')
 
@@ -440,34 +440,34 @@ def main():
     check_git_remote()
 
     branches = get_json("%s/branches" % GITHUB_API_BASE)
-    branch_names = filter(lambda x: x.startswith(RELEASE_BRANCH_PREFIX), [x['name'] for x in branches])
+    branch_names = [x for x in [x['name'] for x in branches] if x.startswith(RELEASE_BRANCH_PREFIX)]
     # Assumes branch names can be sorted lexicographically
     latest_branch = sorted(branch_names, reverse=True)[0]
 
-    pr_num = raw_input("Which pull request would you like to merge? (e.g. 34): ")
+    pr_num = input("Which pull request would you like to merge? (e.g. 34): ")
     pr = get_json("%s/pulls/%s" % (GITHUB_API_BASE, pr_num))
     pr_events = get_json("%s/issues/%s/events" % (GITHUB_API_BASE, pr_num))
 
     url = pr["url"]
 
     pr_title = pr["title"]
-    commit_title = raw_input("Commit title [%s]: " % pr_title.encode("utf-8")).decode("utf-8")
+    commit_title = input("Commit title [%s]: " % pr_title)
     if commit_title == "":
         commit_title = pr_title
 
     # Decide whether to use the modified title or not
     modified_title = standardize_jira_ref(commit_title)
     if modified_title != commit_title:
-        print "I've re-written the title as follows to match the standard format:"
-        print "Original: %s" % commit_title
-        print "Modified: %s" % modified_title
-        result = raw_input("Would you like to use the modified title? (y/n): ")
+        print("I've re-written the title as follows to match the standard format:")
+        print("Original: %s" % commit_title)
+        print("Modified: %s" % modified_title)
+        result = input("Would you like to use the modified title? (y/n): ")
         if result.lower().strip() == "y":
             commit_title = modified_title
-            print "Using modified title:"
+            print("Using modified title:")
         else:
-            print "Using original title:"
-        print commit_title
+            print("Using original title:")
+        print(commit_title)
 
     body = pr["body"]
     target_ref = pr["base"]["ref"]
@@ -484,13 +484,13 @@ def main():
         merge_hash = merge_commits[0]["commit_id"]
         message = get_json("%s/commits/%s" % (GITHUB_API_BASE, merge_hash))["commit"]["message"]
 
-        print "Pull request %s has already been merged, assuming you want to backport" % pr_num
+        print("Pull request %s has already been merged, assuming you want to backport" % pr_num)
         commit_is_downloaded = run_cmd(['git', 'rev-parse', '--quiet', '--verify',
                                     "%s^{commit}" % merge_hash]).strip() != ""
         if not commit_is_downloaded:
             fail("Couldn't find any merge commit for #%s, you may need to update HEAD." % pr_num)
 
-        print "Found commit %s:\n%s" % (merge_hash, message)
+        print("Found commit %s:\n%s" % (merge_hash, message))
         cherry_pick(pr_num, merge_hash, latest_branch)
         sys.exit(0)
 
@@ -499,17 +499,17 @@ def main():
             "Continue? (experts only!)"
         continue_maybe(msg)
 
-    print ("\n=== Pull Request #%s ===" % pr_num)
-    print ("PR title\t%s\nCommit title\t%s\nSource\t\t%s\nTarget\t\t%s\nURL\t\t%s" % (
-        pr_title, commit_title, pr_repo_desc, target_ref, url))
+    print(("\n=== Pull Request #%s ===" % pr_num))
+    print(("PR title\t%s\nCommit title\t%s\nSource\t\t%s\nTarget\t\t%s\nURL\t\t%s" % (
+        pr_title, commit_title, pr_repo_desc, target_ref, url)))
     continue_maybe("Proceed with merging pull request #%s?" % pr_num)
 
     merged_refs = [target_ref]
 
     merge_hash = merge_pr(pr_num, target_ref, commit_title, body, pr_repo_desc)
 
     pick_prompt = "Would you like to pick %s into another branch?" % merge_hash
-    while raw_input("\n%s (y/n): " % pick_prompt).lower().strip() == "y":
+    while input("\n%s (y/n): " % pick_prompt).lower().strip() == "y":
         merged_refs = merged_refs + [cherry_pick(pr_num, merge_hash, latest_branch)]
 
     if JIRA_IMPORTED:
@@ -518,11 +518,11 @@ def main():
             jira_comment = "Issue resolved by pull request %s\n[%s/%s]" % (pr_num, GITHUB_BASE, pr_num)
             resolve_jira_issues(commit_title, merged_refs, jira_comment)
         else:
-            print "JIRA_USERNAME and JIRA_PASSWORD not set"
-            print "Exiting without trying to close the associated JIRA."
+            print("JIRA_USERNAME and JIRA_PASSWORD not set")
+            print("Exiting without trying to close the associated JIRA.")
     else:
-        print "Could not find jira-python library. Run 'sudo pip install jira' to install."
-        print "Exiting without trying to close the associated JIRA."
+        print("Could not find jira-python library. Run 'sudo pip install jira' to install.")
+        print("Exiting without trying to close the associated JIRA.")
 
 if __name__ == "__main__":
     import doctest