微信公眾號：數據運營人
本系列為博主的讀書學習筆記，如需轉載請註明出處。

第一章 語言處理與python

1.4 回到python：決策和控制條件對每個元素進行操作嵌套代碼塊條件循環

1.4 回到python：決策和控制

條件

• 數值比較運算符

列表生成式和關系運算符

print(sent7)
print([w for w in sent7 if len(w)<4])
print([w for w in
 
 sent7 if len(w)<=4])
print([w for w in sent7 if len(w)==4])
print([w for w in sent7 if len(w)!=4])

返回結果：

• 一些詞比較運算符

列表生成式和字符串比較運算符

print(sorted([w for w in set(text1) if w.endswith(‘ableness‘)]))
print(sorted([term for term in set(text4) if ‘gnt‘in term]))
print(sorted([item for item in set(text6)if item.istitle()]))
print(sorted([item for
 
 item in set(sent7)if item.isdigit()]))

列表生成式多條件

print(sorted([w for w in set(text7)if ‘-‘ in w and ‘index‘ in w]))
print(sorted([wd for wd in set(text3) if wd.istitle() and len(wd)> 10]))
print(sorted([w for w in set(sent7) if not w.islower()]))
print(sorted([t for t in set(text2) if ‘cie‘ in t or ‘cei‘ in t]))

對每個元素進行操作

print([len(w) for w in text1])
print([w.upper() for w in text1])
print(len(text1))
print(len(set(text1)))
print(set([word.lower() for word in text1]))
print(len(set([word.lower() for word in text1 if word.isalpha()])))

嵌套代碼塊

ord = ‘cat‘
if len(word) < 5:
    print (‘word length is less than 5‘)
else:
    print(‘word length is more than 5‘)

條件循環

# if 條件
sent1 = [‘Call‘,‘me‘,‘Ishmael‘,‘.‘]
for i in sent1:
    if i.endswith(‘l‘):
        print(i)
# if…elif…else條件
for token in sent1:
    if token.islower():
        print (token, ‘is a lowercase word‘)
    elif token.istitle():
        print (token, ‘is a titlecase word‘)
    else:
        print (token, ‘is punctuation‘)

python自然語言處理——1.4 回到python：決策和控制