python數據分析基礎

1.python操作csv數據文件

#encoding:utf-8
import csv
with open('data/grades.csv') as csvfile:
    grades_data=list(csv.DictReader(csvfile))
print('記錄個數：',len(grades_data))
avg_assign1 = sum([float(row['assignment1_grade']) for row in grades_data]) / len(grades_data)
print('assignment1平均分數：', avg_assign1)
assign1_sub_month = set(row['assignment1_submission'][:7] for row in grades_data)
print(assign1_sub_month)

2. 科學計算庫Numpy

(1)創建array

array 名詞，數組，隊列，陣列

python中的list和array的不同之處

import numpy as np
my_list = [1,2,3]
x = np.array(my_list)
print('列表：',my_list)
print('Arrary:',x)
a = np.array([1,4,6,'d'])   # 參數是列表
b = np.array((1,49,'h'))    # 參數是元組
c = np.array([[1,2,3],[4,5,6]])  # 參數是二維數組
print(a)
print(b)
print(c)