Python – Extract Numerical Dictionary values

• Last Updated : 04 May, 2020

Sometimes, while working with Python Dictionaries, we can have a problem in which we need to extract only if a particular key index is numeric value from the dictionaries which are in form of strings. This can be desired in applications in which we require to do preprocessing. Let’s discuss certain ways in which this task can be performed.

Input : test_dict = {‘best’: [‘5′, ’35’, ‘geeks’], ‘CS’: [1, 2, 3], ‘Gfg’: [‘124’, ‘4’, ‘8’]}
Output : [(‘5’, 1, ‘124’), (’35’, 2, ‘4’)]

Input : test_dict = {“Gfg” : [“4”], ‘best’ : [“6”], ‘CS’ : [1]}
Output : [(‘6’, 1, ‘4’)]

Method #1 : Using loop + `zip() + isdigit()`
The combination of above functions can be used to perform this task. In this, we check for numeric string using isdigit() and zip to perform the cumulation of keys.

 `# Python3 code to demonstrate working of ``# Extract Numerical Dictionary values``# Using loop + zip() + isdigit()`` ` `# initializing dictionary``test_dict ``=` `{``"Gfg"` `: [``"34"``, ``"45"``, ``'geeks'``], ``'is'` `: [``"875"``, ``None``, ``"15"``], ``'best'` `: [``"98"``, ``'abc'``, ``'12k'``]}`` ` `# printing original dictionary``print``(``"The original dictionary : "` `+` `str``(test_dict))`` ` `# Extract Numerical Dictionary values``# Using loop + zip() + isdigit()``res ``=` `[]``for` `a, b, c ``in` `zip``(``*``test_dict.values()):``    ``if` `a.isdigit() :``        ``res.append((a, b, c))``     ` `# printing result ``print``(``"The Numerical values : "` `+` `str``(res)) `
Output :

The original dictionary : {‘Gfg’: [’34’, ’45’, ‘geeks’], ‘best’: [’98’, ‘abc’, ’12k’], ‘is’: [‘875′, None, ’15’]}
The Numerical values : [(’34’, ’98’, ‘875’), (’45’, ‘abc’, None)]

Method #2 : Using list comprehension + `zip() + isdigit()`
The combination of above functions can be used to solve this problem. In this, we perform similar task as above method but as a shorthand using list comprehension.

 `# Python3 code to demonstrate working of ``# Extract Numerical Dictionary values``# Using list comprehension + zip() + isdigit()`` ` `# initializing dictionary``test_dict ``=` `{``"Gfg"` `: [``"34"``, ``"45"``, ``'geeks'``], ``'is'` `: [``"875"``, ``None``, ``"15"``], ``'best'` `: [``"98"``, ``'abc'``, ``'12k'``]}`` ` `# printing original dictionary``print``(``"The original dictionary : "` `+` `str``(test_dict))`` ` `# Extract Numerical Dictionary values``# Using list comprehension + zip() + isdigit()``res ``=` `[(a, b, c) ``for` `a, b, c ``in` `zip``(``*``test_dict.values()) ``if` `a.isdigit()]``     ` `# printing result ``print``(``"The Numerical values : "` `+` `str``(res)) `
Output :

The original dictionary : {‘Gfg’: [’34’, ’45’, ‘geeks’], ‘best’: [’98’, ‘abc’, ’12k’], ‘is’: [‘875′, None, ’15’]}
The Numerical values : [(’34’, ’98’, ‘875’), (’45’, ‘abc’, None)]

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