如何找到csv文件中一列的平均值?

Question

我试图找到这个csv文件中列的平均值。我成功地读取了csv文件:

from numpy import genfromtxt
emp_code = genfromtxt('C:\Users\V\Desktop\data science\DS1_C4_S1_Numpy_PracticeBrief.csv', delimiter=',', dtype=None)
emp_code
array([['1', '22'],
['2', '27'],
['3', '31'],
['4', '29'],
['5', '27'],
['6', '26'],
['7', '27'],
['8', '23'],
['9', '27'],
['10', '32'],
['11', '28'],
['12', '27'],
['13', '22'],
['14', '27'],
['15', '35'],
['16', '33'],
['17', '28'],
['18', '22'],
['19', '25'],
['20', '27'],
['21', '37'],
['22', '27'],
['23', '24'],
['24', '27'],
['25', '28'],
['26', '26'],
['27', '27'],
['28', '27'],
['29', '29'],
['30', '49'],
['31', '26'],
['32', '32'],
['33', '26'],
['34', '24'],
['35', '24'],
['36', '23'],
['37', '28'],
['38', '28'],
['39', '22'],
['40', '26'],
['41', '32'],
['42', '35'],
['43', '33'],
['44', '31'],
['45', '30'],
['46', '36'],
['47', '22'],
['48', '23'],
['49', '32'],
['50', '34']], dtype='<U2')

现在，我想找出平均年龄。我不确定怎样才能找到它。是np.mean['Age']吗?编辑:我尝试了emp_code[:，1].mean()，它给出了一个错误。这是一个打字错误，所以我不能理解它背后的原因。

Answer 1

数据类型有一个问题。您可能需要对进行类型转换(转换)，或者从文本文件中读取浮点数作为数据类型。

从文本文件中读取浮点数:

emp_code = genfromtxt('C:\Path\to\csv\DS1_C4_S1_Numpy_PracticeBrief.csv', delimiter=',', dtype=np.float64)
mean_age = emp_code[:,1].mean()

此代码可以帮助您将numpy数组转换为浮点数并获得平均年龄。

emp_code = np.asarray(emp_code, dtype=np.float64)
mean_age = emp_code[:,1].mean()