Totally new to Python OOP. I am trying to write a code to separate anagrams (https://en.wikipedia.org/wiki/Anagram) in a list. The original question from Leetcode is here (https://leetcode.com/problems/anagrams/) For example:
strs=["eat", "tea", "tan", "ate", "nat", "bat"]
It should return:
[['eat', 'tea','tan','ate','nat'], ['bat']]
I see some discussion codes like (https://leetcode.com/discuss/51190/1-line-ruby-python-for-updated-problem):
def groupAnagrams(self, strs):
groups = collections.defaultdict(list)
for s in strs:
groups[tuple(sorted(s))].append(s)
return map(sorted, groups.values())
Or (https://leetcode.com/discuss/83032/without-sorting-each-string-use-hash-instead-concise-python)
def groupAnagrams(self, strs):
dic = collections.defaultdict(list)
for str in strs:
dic[reduce(operator.mul, map(hash, str), 1)].append(str)
return map(sorted, dic.values())
The question is: how can I make this class/function runs to take the list "strs"
as an input and output the desired list?
groupAnagrams(self,list1)
NameError: name 'self' is not defined
Call class then we will use the method:
class A(object):
some_method = groupAnagrams
a = A()
print a.some_method(list1)
this will give us:
[['bat'], ['ate', 'eat', 'tea'], ['nat', 'tan']]
Related
Consider the following code:
def add_function(a, b):
c = str(a) + b
print "c is %s" % c
def add_int_function(c, d):
e = c + d
print "the vaule of e is %d" % e
if __name__ =="__main__":
add_function(59906, 'kugrt5')
add_int_function(1, 2)
It always shows me: "expected 2 blank lines ，found 1" in aadd_int_function, but not in the add_function.
When I add two spaces in front of the def add_int_function(c, d):
there is a error shows unindent does not match any outer indentation level
in the end of add_function:
Just add another line between your function definitions :
1 line :
2 lines:
This is a pretty common question within the python community. After the release of PEP 8, new formatting styles were accepted into python. One of them states that after the definition of a class or function there must be two lines separating them. As such:
def yadayada:
print("two lines between the functions")
def secondyadayada:
print("this is the proper formatting")
So, you should never do it like:
def yadayada:
print("two lines between the functions")
def secondyadayada:
print("this is the proper formatting")
Or else PyCharm will throw that error at you.
Further clarification on #kennet-celeste & #shreyshrey 's answers,
Each function or class defined requires 2 spaces above and 2 spaces below. Unless the function is the last item in the script, in which the expected format is one blank line as an End of File marker. So:
# some code followed by 2 blank spaces
def function1():
def function2():
def function3():
For people who wonders why it requires two blank lines
if you were to write in other languages it would be:
fun doSth() {
print()
}
fun doSth1() {
print()
}
but if you were to delete all the curly braces from the code you will see:
two blank lines between methods
fun doSth()
print()
#
#
fun doSth1()
print()
#
I've to figure out the given statement is question or normal statement without defining any chunk grammar. I tried drawing a tree which needs grammer but it doesn't tell me whether it is a question or statement. Penn Treebank is one solution I've heard of but couldn't find any help for this
train_text = state_union.raw("text1.txt")
sample_text = state_union.raw("text2.txt")
custom_sent_tokenizer = PunktSentenceTokenizer(train_text)
#PunktSentenceTokenizer is an abtract class for sent_tokenizer()
tokenized = custom_sent_tokenizer.tokenize(sample_text)
##print (custom_sent_tokenizer)
print (tokenized)
try:
for i in tokenized:
words = nltk.word_tokenize(i)
tagged = nltk.pos_tag(words)
print tagged
chunkGram = r"""Chunk: {<RB.?>*<VB.?>*<NNP>+<NN>?}"""
chunkParser = nltk.RegexpParser(chunkGram)
chunked = chunkParser.parse(tagged)
print chunked
chunked.draw()
except Exception as e:
print(str(e))
In my code below, I keep getting an error that I cant tell how to fix it.
See code:
def WordSelector():
global pattern
words = [location]
corpus = " ".join(words)
sentences1 = re.split(r'\.', corpus)
name17 = [name66, name666, name67, name68, name69, name612]
k1 = iter(name17)
keyword = next(k1)
pattern1 = keyword
class LocalBreak(Exception):
pass
try:
for pattern1 in name17:
for sentence in sentences1:
if pattern1 in sentence:
print 'code'
raise LocalBreak()
except LocalBreak:
pass
WordSelector()
I keep getting this error:
"C:\Python27\synonyms3.py", line 72, in LocalBreak
except LocalBreak:
NameError: free variable 'LocalBreak' referenced before assignment in enclosing scope
Whole try/except block is defined inside LocalBreak body, where you cannot reference class itself (since it's definition is not yet done).
Simply indent your code correctly and do your looping in fuction body, not in custom Exception definition scope.
def WordSelector():
global pattern
words = [location]
corpus = " ".join(words)
sentences1 = re.split(r'\.', corpus)
name17 = [name66, name666, name67, name68, name69, name612]
k1 = iter(name17)
keyword = next(k1)
pattern1 = keyword
class LocalBreak(Exception):
pass
try:
for pattern1 in name17:
for sentence in sentences1:
if pattern1 in sentence:
print 'code'
raise LocalBreak()
except LocalBreak:
pass
WordSelector()
I have the following function defined:
def displayHand(hand):
"""
Displays the letters currently in the hand.
For example:
>>> displayHand({'a':1, 'x':2, 'l':3, 'e':1})
Should print out something like:
a x x l l l e
The order of the letters is unimportant.
hand: dictionary (string -> int)
"""
for letter in hand.keys():
for j in range(hand[letter]):
print letter, # print all on the same line
print '' # print an empty line
Now, I want to print the following:
Current hand: a b c
To do this, I try to do:
print "Current hand: ", displayHand({'a':1, 'b':1, 'c':1})
And I get:
Current hand: a b c
None
I know that None is printed cause I am calling the print function on the displayHand(hand) function, which doesn't return anything.
Is there any way to get rid of that "None" without modifying displayHand(hand)?
if you want to use your function in a print statement, it should return a string and not print something itself (and return None) - as you would do in a __str__ method of a class. something like:
def displayHand(hand):
ret = ''
for letter in hand.keys():
for j in range(hand[letter]):
ret += '{} '.format(letter) # print all on the same line
# ret += '\n'
return ret
or even
def displayHand(hand):
return ''.join(n*'{} '.format(k) for k,n in hand.items() )
When you trail a print with a ,, the next print will appear on the same line, so you should just call the two things on separate lines, as in:
def printStuff():
print "Current hand: ",
displayHand({'a':1, 'b':1, 'c':1})
Of course you could just adapt this and create a method like:
def printCurrentHand(hand):
print "Current hand: ",
displayHand(hand)
The only way to do this (or I believe the only way to do this) is to use return instead of print in your displayhand() function. Sorry if I didn't answer your question.
Your function 'displayHand' does not have to print the output,
it has to return a string.
def displayHand(hand):
mystring=''
for letter in hand.keys():
for j in range(hand[letter]):
mystring+= letter # concatenate all on the same line
return mystring
BUT, you have to check the '.keys' command help as the order of the input (a/b/c) may not be respected
I am learning python - this is my first programming language that I am learning. I am a little confused about one line of the code. The full code can also be found at http://learnpythonthehardway.org/book/ex41.html
import random
from urllib import urlopen
import sys
WORD_URL = "http://learncodethehardway.org/words.txt"
WORDS = []
PHRASES = {
"class %%%(%%%):":
"Make a class named %%% that is-a %%%.",
"class %%%(object):\n\tdef __init__(self, ***)" :
"class %%% has-a __init__ that takes self and *** parameters.",
"class %%%(object):\n\tdef ***(self, ###)":
"class %%% has-a function named *** that takes self and ### parameters.",
"*** = %%%()":
"Set *** to an instance of class %%%.",
"***.***(###)":
"From *** get the *** function, and call it with parameters self, ###.",
"***.*** = '***'":
"From *** get the *** attribute and set it to '***'."
}
# do they want to drill phrases first
PHRASE_FIRST = False
if len(sys.argv) == 2 and sys.argv[1] == "english":
PHRASE_FIRST = True
# load up the words from the website
for word in urlopen(WORD_URL).readlines():
WORDS.append(word.strip())
def convert(snippet, phrase):
class_names = [w.capitalize() for w in
random.sample(WORDS, snippet.count("%%%"))]
other_names = random.sample(WORDS, snippet.count("***"))
results = []
param_names = []
for i in range (0, snippet.count("###")):
param_count = random.randint(1,3)
param_names.append(', '.join(random.sample(WORDS, param_count)))
for sentence in snippet, phrase:
result = sentence[:]
# fake class name
for word in class_names:
result = result.replace("***", word, 1)
# fake other names
for word in other_names:
result = result.replace("***", word, 1)
# fake parameter lists
for word in param_names:
result = result.replace("###", word, 1)
results.append(result)
return results
# keep going until they hit CTRL-D
try:
while True:
snippets = PHRASES.keys()
# returns a randomly shuffled dictionary keys list
random.shuffle(snippets)
for snippet in snippets:
phrase = PHRASES[snippet]
question, answer = convert(snippet, phrase)
if PHRASE_FIRST:
question, answer = answer, question
print question
raw_input("> ")
print "ANSWER: %s\n\n" % answer
except EOFError:
print "\nBye"
It is the 11th line of code from the bottom that I don't quite understand: phrase = PHRASES[snippet]. Since snippet in for snippet in snippets: is looping through the keys of the randomized-shuffled PHRASES list, why can't the code simply be phrase = snippet. Thanks in advance for any help.
Cheers - Darren
get the value of key"snippet" in the dictionary