NameError: name 'search_query' is not defined

NameError: name 'search_query' is not defined.

#!/usr/bin/env python3

import datetime
import sys

from peewee import *
from collections import OrderedDict


db = SqliteDatabase('diary.db')



class Entry(Model):
  content = TextField() #Holds whatever text we want it to hold
  timestamp = DateTimeField(default=datetime.datetime.now)

  class Meta:
    database = db

def initalize():
  db.connect()
  db.create_tables([Entry], safe=True)

def menu_loop():
  choice = None #Makes it a pointless variable. (giving it without a value)

  while choice != 'q': #While its not equal to q
    print("Enter 'q' to quit.")
    for key, value in menu.items():  #KGets the key of the dict, and the value of the dict.a
      print('{}) {}'.format(key, value.__doc__)) #The values are functions, reads the doc of 
    choice = input('Action: ').lower().strip()

    if choice in menu:
      menu[choice]() #We go back to menu, find the function they selected, and run it.

def add_entry():
  """Add an entry."""
  print('Enter your entry. Press ctrl+d when finished.')
  data = sys.stdin.read().strip()

  if data:
    if input('Save entry? [Y/n ').lower() != 'n':
      Entry.create(content=data)
      print('Saved successfuly.')



def view_entries():
  """View previous entries"""
  entries = Entry.select().order_by(Entry.timestamp.desc())
  if search_query:
    entries = entries.where(Entry.content.contains(search_query))

  for entry in entries:
    timestamp = entry.timestamp.strftime('%A %B %d, %Y %I:%M%p ')
    print(timestamp)
    print('='*len(timestamp))
    print(entry.content)
    print('N) next entry')
    print('q) return to main menu')    
    next_action = input('Action: [N/q] ').lower().strip()
    if next_action == 'q':
      break

def search_entries():
  """Search entries for a string."""
  view_entries(input('Search query: '))

def delete_entry(entry):
  """Delete an entry."""

menu = OrderedDict([
    ('a', add_entry),
    ('v', view_entries),
  ])

if __name__ == '__main__':
  initalize()
  menu_loop()