Αποτελέσματα Αναζήτησης
21 Φεβ 2017 · There isn't one as far as I know of, one way however to do it is to create a dict for normal lookup by key and another dict for reverse lookup by value. There's an example of such an implementation here: http://code.activestate.com/recipes/415903-two-dict-classes-which-can-lookup-keys-by-value-an/
3 Ιαν 2020 · Today, we’re taking a look at dictionaries and how we can perform a reverse dictionary lookup. In words, how do we get a key from a dictionary given a value? As it turns out, there are three main solutions. First, we could try explicitly looping over the dictionary using something like. Alternatively, we could create a generator expression:
24 Οκτ 2020 · import pandas as pd sheets_dict = pd.read_excel('Book1.xlsx', sheetname=None) full_table = pd.DataFrame() for name, sheet in sheets_dict.items(): sheet['sheet'] = name sheet = sheet.rename(columns=lambda x: x.split('\n')[-1]) full_table = full_table.append(sheet) full_table.reset_index(inplace=True, drop=True) print full_table
26 Φεβ 2024 · There are a few ways you can do a reverse dictionary lookup in Python. The easiest way to perform a reverse dictionary lookup in Python is with a for loop. Below is an example showing you how to perform a reverse dictionary lookup using a for loop in your Python code. if value == "Bobby": print(key)
def ValLookup(Dic,v): if v in Dic.values(): return next(key for key, val in Dic.items() if val == v) else: return 'None' If you need to do this, you really should just keep a separate dictionary as a reverse index. This method gets slow.
15 Νοε 2024 · Let’s explore some effective solutions and methods for performing an inverse lookup operation in Python. A common approach to find a key by value is using a list comprehension: In this example, dict_obj refers to the dictionary you are querying, and ‘desired_value’ is the value you’re searching for.
Given a dictionary d and a key k, it is easy to find the corresponding value v = d[k]. This operation is called a lookup. But what if you have v and you want to find k? You have two problems: first, there might be more than one key that maps to the value v.
