python建立哈希表_如何在python中为大数据创建哈希表？

文本文件可能有重复项，这将覆盖字典中现有的键(哈希表的python名称)。您可以创建一组唯一的键，然后使用字典理解来填充字典。在

样本_文件.txta

b

c

c

Python代码

^{pr2}$

这是一个包含100万个长度为10的随机字母字符的实现。时间安排在半秒以下是相对微不足道的。在import string

import numpy as np

letter_map = {n: letter for n, letter in enumerate(string.ascii_lowercase, 1)}

long_alpha_list = ["".join([letter_map[number] for number in row]) + "\n"

for row in np.random.random_integers(1, 26, (1000000, 10))]

>>> long_alpha_list[:5]

['mfeeidurfc\n',

'njbfzpunzi\n',

'yrazcjnegf\n',

'wpuxpaqhhs\n',

'fpncybprrn\n']

>>> len(long_alpha_list)

1000000

# Write list to file.

with open('sample_file.txt', 'wb') as f:

f.writelines(long_alpha_list)

# Read them back into a dictionary per the method above.

with open("sample_file.txt") as f:

keys = set(line.strip() for line in f.readlines())

>>> %%timeit -n 10

>>> my_dict = {key: 1 for key in keys if key}

10 loops, best of 3: 379 ms per loop