データクレンジング

意味の同じ要素を一つに統合

2018年1月16日 by 河副太智 Leave a Comment

‘Ms’, ‘Miss’の２つは同じ意味なのでこういったものを一つに統合

O’Driscoll, Miss. Bridget

Samaan, Mr. Youssef

Arnold-Franchi, Mrs. Josef (Josefine Franchi)

Panula, Master. Juha Niilo

Nosworthy, Mr. Richard Cater

Harper, Mrs. Henry Sleeper (Myna Haxtun)

Faunthorpe, Mrs. Lizzie (Elizabeth Anne Wilkinson)

Ostby, Mr. Engelhart Cornelius

Woolner, Mr. Hugh

def get_title(name):
	title_search = re.search(' ([A-Za-z]+)\.', name)
	# If the title exists, extract and return it.
	if title_search:
		return title_search.group(1)
	return ""

for dataset in full_data:
    dataset['Title'] = dataset['Name'].apply(get_title)

print(pd.crosstab(train['Title'], train['Sex']))

def get_title(name):

title_search = re.search(' ([A-Za-z]+)\.', name)

# If the title exists, extract and return it.

if title_search:

return title_search.group(1)

return ""

for dataset in full_data:

dataset['Title'] = dataset['Name'].apply(get_title)

print(pd.crosstab(train['Title'], train['Sex']))

上記の結果以下のように名前のタイトルの一覧が出る

Sex       female  male
Title                 
Capt           0     1
Col            0     2
Countess       1     0
Don            0     1
Dr             1     6
Jonkheer       0     1
Lady           1     0
Major          0     2
Master         0    40
Miss         182     0
Mlle           2     0
Mme            1     0
Mr             0   517
Mrs          125     0
Ms             1     0
Rev            0     6
Sir            0     1

Sex female male

Title

Capt 0 1

Col 0 2

Countess 1 0

Don 0 1

Dr 1 6

Jonkheer 0 1

Lady 1 0

Major 0 2

Master 0 40

Miss 182 0

Mlle 2 0

Mme 1 0

Mr 0 517

Mrs 125 0

Ms 1 0

Rev 0 6

Sir 0 1

同じ意味の物を統合する

for dataset in full_data:
    dataset['Title'] = dataset['Title'].replace(['Lady', 'Countess','Capt', 'Col',\
 	'Don', 'Dr', 'Major', 'Rev', 'Sir', 'Jonkheer', 'Dona'], 'Rare')

    dataset['Title'] = dataset['Title'].replace('Mlle', 'Miss')
    dataset['Title'] = dataset['Title'].replace('Ms', 'Miss')
    dataset['Title'] = dataset['Title'].replace('Mme', 'Mrs')

print (train[['Title', 'Survived']].groupby(['Title'], as_index=False).mean())

for dataset in full_data:

dataset['Title'] = dataset['Title'].replace(['Lady', 'Countess','Capt', 'Col',\

'Don', 'Dr', 'Major', 'Rev', 'Sir', 'Jonkheer', 'Dona'], 'Rare')

dataset['Title'] = dataset['Title'].replace('Mlle', 'Miss')

dataset['Title'] = dataset['Title'].replace('Ms', 'Miss')

dataset['Title'] = dataset['Title'].replace('Mme', 'Mrs')

print (train[['Title', 'Survived']].groupby(['Title'], as_index=False).mean())

結果

   Title  Survived
0  Master  0.575000
1    Miss  0.702703
2      Mr  0.156673
3     Mrs  0.793651
4    Rare  0.347826

Title Survived

0 Master 0.575000

1 Miss 0.702703

2 Mr 0.156673

3 Mrs 0.793651

4 Rare 0.347826

データクリーニング

2018年1月16日 by 河副太智 Leave a Comment

データクリーニング、データクレンジング

Data CleaningPython

df.columns = ['a','b','c'] # Renames columns
pd.isnull() # Checks for null Values, Returns Boolean Array
pd.notnull() # Opposite of s.isnull()
df.dropna() # Drops all rows that contain null values
df.dropna(axis=1) # Drops all columns that contain null values
df.dropna(axis=1,thresh=n) # Drops all rows have have less than n non null values
df.fillna(x) # Replaces all null values with x
s.fillna(s.mean()) # Replaces all null values with the mean (mean can be replaced with almost any function from the statistics section)
s.astype(float) # Converts the datatype of the series to float
s.replace(1,'one') # Replaces all values equal to 1 with 'one'
s.replace([1,3],['one','three']) # Replaces all 1 with 'one' and 3 with 'three'
df.rename(columns=lambda x: x + 1) # Mass renaming of columns
df.rename(columns={'old_name': 'new_ name'}) # Selective renaming
df.set_index('column_one') # Changes the index
df.rename(index=lambda x: x + 1) # Mass renaming of index

Data CleaningPython

df.columns = ['a','b','c'] # Renames columns

pd.isnull() # Checks for null Values, Returns Boolean Array

pd.notnull() # Opposite of s.isnull()

df.dropna() # Drops all rows that contain null values

df.dropna(axis=1) # Drops all columns that contain null values

df.dropna(axis=1,thresh=n) # Drops all rows have have less than n non null values

df.fillna(x) # Replaces all null values with x

s.fillna(s.mean()) # Replaces all null values with the mean (mean can be replaced with almost any function from the statistics section)

s.astype(float) # Converts the datatype of the series to float

s.replace(1,'one') # Replaces all values equal to 1 with 'one'

s.replace([1,3],['one','three']) # Replaces all 1 with 'one' and 3 with 'three'

df.rename(columns=lambda x: x + 1) # Mass renaming of columns

df.rename(columns={'old_name': 'new_ name'}) # Selective renaming

df.set_index('column_one') # Changes the index

df.rename(index=lambda x: x + 1) # Mass renaming of index

#欠損値処理　(欠損値の指定defaultは’NaN’,mean, median, mode のどれか,行か列かの指定
med_imp = Imputer(missing_values=0, strategy=’median’, axis=0)
med_imp.fit(X.iloc[:, 1:6])
X.iloc[:, 1:6] = med_imp.transform(X.iloc[:, 1:6])

missing_values
これで欠損値であるものを指定。 defaultは’NaN’

strategy
ここで、mean, median, mode のどれかを指定します。

axis
行か列かの指定

verbose
理論値

copy
コピーするか、元のデータ自体に変更を加えるかの指定

不要なデータを削除する flag,dummy,drop

2017年12月13日 by 河副太智 Leave a Comment

# url
mush_data_url = "http://archive.ics.uci.edu/ml/machine-learning-databases/mushroom/agaricus-lepiota.data"
s = requests.get(mush_data_url).content

# データの形式変換
mush_data = pd.read_csv(io.StringIO(s.decode('utf-8')), header=None)

# データに名前をつける(データを扱いやすくするため)
mush_data.columns = ["classes", "cap_shape", "cap_surface", "cap_color", "odor", "bruises",
                     "gill_attachment", "gill_spacing", "gill_size", "gill_color", "stalk_shape",
                     "stalk_root", "stalk_surface_above_ring", "stalk_surface_below_ring",
                     "stalk_color_above_ring", "stalk_color_below_ring", "veil_type", "veil_color",
                     "ring_number", "ring_type", "spore_print_color", "population", "habitat"]

# カテゴリー変数(色の種類など数字の大小が決められないもの)をダミー特徴量(yes or no)として変換する
mush_data_dummy = pd.get_dummies(
    mush_data[['gill_color', 'gill_attachment', 'odor', 'cap_color']])

print(mush_data)
# 目的変数：flg立てをする
mush_data_dummy["flg"] = mush_data["classes"].map(
    lambda x: 1 if x == 'p' else 0)

# 説明変数と目的変数
X = mush_data_dummy.drop("flg", axis=1)
Y = mush_data_dummy['flg']

# url

mush_data_url = "http://archive.ics.uci.edu/ml/machine-learning-databases/mushroom/agaricus-lepiota.data"

s = requests.get(mush_data_url).content

# データの形式変換

mush_data = pd.read_csv(io.StringIO(s.decode('utf-8')), header=None)

# データに名前をつける(データを扱いやすくするため)

mush_data.columns = ["classes", "cap_shape", "cap_surface", "cap_color", "odor", "bruises",

"gill_attachment", "gill_spacing", "gill_size", "gill_color", "stalk_shape",

"stalk_root", "stalk_surface_above_ring", "stalk_surface_below_ring",

"stalk_color_above_ring", "stalk_color_below_ring", "veil_type", "veil_color",

"ring_number", "ring_type", "spore_print_color", "population", "habitat"]

# カテゴリー変数(色の種類など数字の大小が決められないもの)をダミー特徴量(yes or no)として変換する

mush_data_dummy = pd.get_dummies(

mush_data[['gill_color', 'gill_attachment', 'odor', 'cap_color']])

print(mush_data)

# 目的変数：flg立てをする

mush_data_dummy["flg"] = mush_data["classes"].map(

lambda x: 1 if x == 'p' else 0)

# 説明変数と目的変数

X = mush_data_dummy.drop("flg", axis=1)

Y = mush_data_dummy['flg']

辞書の文字数カウント　collectionsモジュールのdefaultdict(型)

2017年11月28日 by 河副太智 Leave a Comment

jisho = defaultdict(intかlist等の型)

#これで変数jishoが辞書になる

例

from collections import defaultdict

jisho = defaultdict(int)
lst = [“a”, “b”, “c”, “b”, “a”, “e”]

for key in lst:
jisho[key] += 1

print (jisho)

 例:2
<span role="presentation"><span class="cm-keyword">from</span> <span class="cm-variable">collections</span> <span class="cm-keyword">import</span> <span class="cm-variable">defaultdict</span> </span>

				1

						<span role="presentation"><span class="cm-keyword">from</span> <span class="cm-variable">collections</span> <span class="cm-keyword">import</span> <span class="cm-variable">defaultdict</span> </span>

<span role="presentation"><span class="cm-comment"># 文字列description</span></span>

				1

						<span role="presentation"><span class="cm-comment"># 文字列description</span></span>

<span role="presentation"><span class="cm-variable">description</span> = <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-variable">description</span> = <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"AFL intends to import  PVC-insulated  and  XLPE-insulated  bunched copper wire from Honduras.  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"AFL intends to import  PVC-insulated  and  XLPE-insulated  bunched copper wire from Honduras.  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"The insulated wire will be used in the U.S. in the production of automotive wire harnesses. "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"The insulated wire will be used in the U.S. in the production of automotive wire harnesses. "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"Copper strands, classifiable under subheading 7413.00, Harmonized Tariff System of the United States  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"Copper strands, classifiable under subheading 7413.00, Harmonized Tariff System of the United States  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"(HTSUS); polyvinyl chloride (PVC) pellets, classifiable under subheading 3904.21, HTSUS; and "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"(HTSUS); polyvinyl chloride (PVC) pellets, classifiable under subheading 3904.21, HTSUS; and "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"cross-link polyethylene (XLPE) pellets, classifiable under subheading 3901.30, HTSUS, all of U.S. origin will be exported to Honduras.  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"cross-link polyethylene (XLPE) pellets, classifiable under subheading 3901.30, HTSUS, all of U.S. origin will be exported to Honduras.  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"The copper strands will be annealed in the U.S. and will be wound onto reels,  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"The copper strands will be annealed in the U.S. and will be wound onto reels,  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"containing between six and 14 untwisted and non-bunched copper strands. In Honduras,  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"containing between six and 14 untwisted and non-bunched copper strands. In Honduras,  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"the strands are fed into a buncher, which arranges the strands in specific geometric orientations,  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"the strands are fed into a buncher, which arranges the strands in specific geometric orientations,  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"with specific twist lengths ( lay lengths ) based on the specifications of the end use application "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"with specific twist lengths ( lay lengths ) based on the specifications of the end use application "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"( lay plate ). The strands then enter the  compaction die  which sets the diameter and length of  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"( lay plate ). The strands then enter the  compaction die  which sets the diameter and length of  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"the specific products, resulting in the creation of  bunched wire.  By using strands of various "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"the specific products, resulting in the creation of  bunched wire.  By using strands of various "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"sizes and numbers of strands, different sizes of bunched wire are produced. It is "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"sizes and numbers of strands, different sizes of bunched wire are produced. It is "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"stated that the size of the bunched wire determines its electrical current carrying capacity  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"stated that the size of the bunched wire determines its electrical current carrying capacity  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"and physical strength. The bunched wire will contain between seven and 104 strands, with American "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"and physical strength. The bunched wire will contain between seven and 104 strands, with American "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"Wire Gauge (AWG) measurements varying between 10 and 22. It is stated that the AWG level identifies the  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"Wire Gauge (AWG) measurements varying between 10 and 22. It is stated that the AWG level identifies the  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"diameter, electrical current capacity and temperature  rating,  or maximum temperature levels within  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"diameter, electrical current capacity and temperature  rating,  or maximum temperature levels within  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"which the wire can function. From the compaction die, the bunched wire enters the  bow , which rotates "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"which the wire can function. From the compaction die, the bunched wire enters the  bow , which rotates "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"and twists the bunched wire, based on the needs of the given end use of the wire. "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"and twists the bunched wire, based on the needs of the given end use of the wire. "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"Next, the bunched wire is wound onto a reel and prepared for insulation with either PVC or XLPE.  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"Next, the bunched wire is wound onto a reel and prepared for insulation with either PVC or XLPE.  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"The compound is melted and pumped through the extruder line. In the extruder line, a  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"The compound is melted and pumped through the extruder line. In the extruder line, a  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"rotating wheel pulls the copper wire, and the compound is extruded over the wire.  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"rotating wheel pulls the copper wire, and the compound is extruded over the wire.  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"If PVC is used, the material is cooled following a controlled cooling with water,  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"If PVC is used, the material is cooled following a controlled cooling with water,  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"which solidifies the compound around the bunched wire. It is stated that PVC-insulated  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"which solidifies the compound around the bunched wire. It is stated that PVC-insulated  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"wire has a lower temperature rating and is more likely to be used in applications  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"wire has a lower temperature rating and is more likely to be used in applications  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"where it is subject to less intense heat. If XLPE is used, a steam vulcanization process  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"where it is subject to less intense heat. If XLPE is used, a steam vulcanization process  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"is required which causes a chemical reaction in the extruded XLPE, causing  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

				1

						<span role="presentation"><span class="cm-string">"is required which causes a chemical reaction in the extruded XLPE, causing  "</span> <span class="cm-operator">+</span> <span class="cm-error">\</span></span>

<span role="presentation"><span class="cm-string">"crosslinking  in the underlying polymer chain. It is stated that  crosslinking"</span></span>

				1

						<span role="presentation"><span class="cm-string">"crosslinking  in the underlying polymer chain. It is stated that  crosslinking"</span></span>

<span role="presentation">​</span>

				1

						<span role="presentation">​</span>

<span role="presentation"><span class="cm-comment"># defaultdictを定義</span></span>

				1

						<span role="presentation"><span class="cm-comment"># defaultdictを定義</span></span>

<span role="presentation"><span class="cm-variable">moji</span> = <span class="cm-variable">defaultdict</span>(<span class="cm-builtin">int</span>)<span class="cm-comment">#これが辞書になる</span></span>

				1

						<span role="presentation"><span class="cm-variable">moji</span> = <span class="cm-variable">defaultdict</span>(<span class="cm-builtin">int</span>)<span class="cm-comment">#これが辞書になる</span></span>

<span role="presentation">​</span>

				1

						<span role="presentation">​</span>

<span role="presentation"><span class="cm-comment"># 文字の出現回数を記録</span></span>

				1

						<span role="presentation"><span class="cm-comment"># 文字の出現回数を記録</span></span>

<span role="presentation"><span class="cm-keyword">for</span> <span class="cm-variable">key</span> <span class="cm-keyword">in</span> <span class="cm-variable">description</span>:</span>

				1

						<span role="presentation"><span class="cm-keyword">for</span> <span class="cm-variable">key</span> <span class="cm-keyword">in</span> <span class="cm-variable">description</span>:</span>

<span role="presentation">    <span class="cm-variable">moji</span>[<span class="cm-variable">key</span>] += <span class="cm-number">1</span></span>

				1

						<span role="presentation">    <span class="cm-variable">moji</span>[<span class="cm-variable">key</span>] += <span class="cm-number">1</span></span>

<span role="presentation">​</span>

				1

						<span role="presentation">​</span>

<span role="presentation"><span class="cm-comment"># ソートし、上位10要素を出力して下さい</span></span>

				1

						<span role="presentation"><span class="cm-comment"># ソートし、上位10要素を出力して下さい</span></span>

<span role="presentation"><span class="cm-builtin">print</span>(<span class="cm-builtin">sorted</span>(<span class="cm-variable">moji</span>.<span class="cm-property">items</span>(), <span class="cm-variable">key</span>=<span class="cm-keyword">lambda</span> <span class="cm-variable">x</span>: <span class="cm-variable">x</span>[<span class="cm-number">1</span>], <span class="cm-variable">reverse</span>=<span class="cm-keyword">True</span>)[:<span class="cm-number">10</span>])</span>

				1

						<span role="presentation"><span class="cm-builtin">print</span>(<span class="cm-builtin">sorted</span>(<span class="cm-variable">moji</span>.<span class="cm-property">items</span>(), <span class="cm-variable">key</span>=<span class="cm-keyword">lambda</span> <span class="cm-variable">x</span>: <span class="cm-variable">x</span>[<span class="cm-number">1</span>], <span class="cm-variable">reverse</span>=<span class="cm-keyword">True</span>)[:<span class="cm-number">10</span>])</span>

<span role="presentation">​</span>

				1

						<span role="presentation">​</span>

結果

[(' ', 428), ('e', 256), ('t', 170), ('i', 163), ('n', 153), ('s', 128), ('a', 124), ('r', 120), ('d', 100), ('o', 98)]

1	[(' ', 428), ('e', 256), ('t', 170), ('i', 163), ('n', 153), ('s', 128), ('a', 124), ('r', 120), ('d', 100), ('o', 98)]

list sort sorted 並び変え

2017年11月28日 by 河副太智 Leave a Comment

listのsort関数は複雑な条件の場合sorted関数のほうがよい

sorted(ソートしたい配列, key=キーとなる関数, reverse=True または False)

reverseをTrueにすると降順
Falseなら昇順

２番目の要素を基に昇順に並び替えるのであれば


<span class="cm-variable">list</span> = [
    [<span class="cm-number">0</span>, 2],
    [<span class="cm-number">1</span>, <span class="cm-number">8</span>],
    [<span class="cm-number">2</span>, <span class="cm-number">10</span>],
    [<span class="cm-number">3</span>, <span class="cm-number">6</span>],
    [<span class="cm-number">4</span>, 18]
]

<span class="cm-builtin">sorted</span>(<span class="cm-variable">list</span>, <span class="cm-variable">key</span>=<span class="cm-keyword">lambda</span> <span class="cm-variable">x</span>: <span class="cm-variable">x</span>[<span class="cm-number">1</span>])

list = [

[0, 2],

[1, 8],

[2, 10],

[3, 6],

[4, 18]

]

sorted(list, key=lambda x: x[1])

</code><code class="cm-s-ipython language-python">

</code><code class="cm-s-ipython language-python">