Python 自动化指南(繁琐工作自动化)第二版:六、字符串操作 https://automatetheboringstuff.com/2e/chapter6/+操作符将两个字符串值连接在一起,但是您可以做得更多。您可以从字符串值中提取部分字符串,添加或删除空格,将字母转换为小写或大写,并检查字符串的格式是否正确。您甚至可以编写Python代码来访问剪贴板,以...
>>>name ='Al'>>>age =4000>>>'My name is %s. I am %s years old.'% (name, age)'My name is Al. I am 4000 years old.' Python 3.6 引入了f-strings,除了用大括号代替了%s,表达式直接放在大括号里面,与字符串插值类似。像原始字符串一样,F 字符串在起始引号前有一个f前缀。在交互式 Shell...
s.rfind(t) # Search for t from end of string s.rindex(t) # Search for t from end of string s.split([delim]) # Split string into list of substrings s.startswith(prefix) # Check if string starts with prefix s.strip() # Strip leading/trailing space s.upper() # Convert to upper...
Output: List of Words =['Welcome', 'To', 'JournalDev'] If you are not familiar with f-prefixed string formatting, please read f-strings in Python If we want to split a string to list based on whitespaces, then we don’t need to provide any separator to the split() function. Also...
freq_dict[word] +=1corpus = [(word, freq_dict[word])forwordinfreq_dict.keys()]returncorpusdefcreate_merge_rule(self, corpus):''' Create a merge rule and add it to the self.merge_rules list. Args: corpus (list[tuple(list, int)]): A list of tuples where the ...
If a list of strings is given it is assumed to be aliases for the column names. index : bool, default True Write row names (index). index_label : str or sequence, or False, default None Column label for index column(s) if desired. If None is given, and `header` and `index`...
Return a copy of the string S in which each character has been mapped through the given translation table. The table must implement lookup/indexing viagetitem, for instance a dictionary or list, mapping Unicode ordinals to Unicode ordinals, strings, or None. If ...
261 262 """ 263 self.attrib[key] = value 264 265 def keys(self): 266 获取当前节点的所有属性的 key 267 268 """Get list of attribute names. 269 270 Names are returned in an arbitrary order, just like an ordinary 271 Python dict. Equivalent to attrib.keys() 272 273 """ 274 return...
df.add_prefix("x_") Trick 4 反转行/列的顺序 drinks.head() drinks[::-1].head() drinks[::-1].reset_index().head() drinks.loc[::-1].reset_index(drop=True).head() ## 加了.loc; 删除旧的 index drinks.loc[:, ::-1].head() ## 反转列的顺序。必须加 .loc Trick 5 基于数据类...
# of each line of text on the clipboard. import pyperclip text = pyperclip.paste() # Separate lines and add stars. lines = text.split('\n') for i in range(len(lines)): # loop through all indexes for "lines" list lines[i] = '* ' + lines[i] # add star to each string in "...