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Python practice problems help beginners to become experts in a python programming language with a small amount of practice effort.
In this python numpy program, we will test whether none of the elements of a given array is zero using Numpy.
import numpy as np
x = np.array([6,0,1,0])
print(np.all(x))
Output :
False
Write a NumPy program to test whether none of the elements of an array is zero.
[6, 8, 3, 5]
True False
np.all(arr) is True when every element is non-zero.import numpy as npprint(np.all(np.array([6, 8, 3, 5])), np.all(np.array([6, 0, 3])))True False
Zero counts as False, so a single 0 makes all False.
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Write a Python program to get the installed NumPy version.
2.5.4
np.__version__.import numpy as npprint(np.__version__)2.5.4
np is the standard alias for NumPy.
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Write a Python program to split a dictionary into dictionaries of n items.
{"a": 1, "b": 2, "c": 3, "d": 4, "e": 5, "f": 6}, n = 3[{'a': 1, 'b': 2, 'c': 3}, {'d': 4, 'e': 5, 'f': 6}]d = {"a": 1, "b": 2, "c": 3, "d": 4, "e": 5, "f": 6}n = 3items = list(d.items())print([dict(items[i:i + n]) for i in range(0, len(items), n)])[{'a': 1, 'b': 2, 'c': 3}, {'d': 4, 'e': 5, 'f': 6}]New to this topic? Read the lesson, then come back.
Write a Python program to map each key to the sum of its list and sort by that sum.
{"x": [1, 5, 6], "y": [4, 8, 2], "c": [3, 9]}{'x': 12, 'c': 12, 'y': 14}d = {"x": [1, 5, 6], "y": [4, 8, 2], "c": [3, 9]}sums = {k: sum(v) for k, v in d.items()}print(dict(sorted(sums.items(), key=lambda kv: kv[1]))){'x': 12, 'c': 12, 'y': 14}New to this topic? Read the lesson, then come back.
Write a Python program to add up the distinct numbers found in all list values.
{"a": [6, 7, 2, 8, 1], "b": [2, 3, 1, 6, 8, 10], "d": [1, 8, 2, 6, 9]}[1, 2, 3, 6, 7, 8, 9, 10] 46
d = {"a": [6, 7, 2, 8, 1], "b": [2, 3, 1, 6, 8, 10], "d": [1, 8, 2, 6, 9]}unique = set().union(*d.values())print(sorted(unique), sum(unique))[1, 2, 3, 6, 7, 8, 9, 10] 46
set().union(*lists) merges all the lists into one set of distinct numbers.
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Write a Python program to reverse each string value and put underscores around each key.
{"a": "Python", "b": "Programming", "c": "Learning"}{'_a_': 'nohtyP', '_b_': 'gnimmargorP', '_c_': 'gninraeL'}[::-1] value.d = {"a": "Python", "b": "Programming", "c": "Learning"}print({f"_{k}_": v[::-1] for k, v in d.items()}){'_a_': 'nohtyP', '_b_': 'gnimmargorP', '_c_': 'gninraeL'}New to this topic? Read the lesson, then come back.
Write a Python program to invert a dictionary whose values repeat, collecting keys in lists.
{"alex": 1, "bob": 2, "martin": 1, "robert": 2}{1: ['alex', 'martin'], 2: ['bob', 'robert']}setdefault(v, []).append(k).d = {"alex": 1, "bob": 2, "martin": 1, "robert": 2}inverted = {}for k, v in d.items(): inverted.setdefault(v, []).append(k)print(inverted){1: ['alex', 'martin'], 2: ['bob', 'robert']}New to this topic? Read the lesson, then come back.
Write a Python program to rename the key “d” to “e”.
{"a": 19, "b": 20, "c": 21, "d": 20}{'a': 19, 'b': 20, 'c': 21, 'e': 20}d["e"] = d.pop("d").d = {"a": 19, "b": 20, "c": 21, "d": 20}d["e"] = d.pop("d")print(d){'a': 19, 'b': 20, 'c': 21, 'e': 20}New to this topic? Read the lesson, then come back.
Write a Python program to delete a list of keys from a dictionary.
{"a": 19, "b": 20, "c": 21, "d": 20, "e": 50}, keys ["a", "d", "e"]{'b': 20, 'c': 21}pop(k, None) for each key.d = {"a": 19, "b": 20, "c": 21, "d": 20, "e": 50}for k in ["a", "d", "e"]: d.pop(k, None)print(d){'b': 20, 'c': 21}New to this topic? Read the lesson, then come back.