如果不是数字/数字 Python，则删除 len 列表

Question

I have random list data like this

data = 
[['No','Name','Job'],
['1','A','A'],
['2','B','B'],
['IS','NOT','NUMBER'],
['3','C','C']]

as you can see if i print(len(data)) it will print 5

how i remove data list and decrease len list

it will print like this

print(data)
    ['1','A','A'],
    ['2','B','B'],
    ['3','C','C']

print(len(data))
3

I already try

for i in range(len(data)):
    if data[i][0].isdigit() == True:
        print(data)

its just show

print(data)
    ['1','A','A'],
    ['2','B','B'],
    ['3','C','C']

not decrease len

Answer 1

data = [['No','Name','Job'], ['1','A','A'], ['2','B','B'], ['IS','NOT','NUMBER'], ['3','C','C']]

print(len(data))
5

data = [x for x in data if x[0].isdigit()]
print(len(data))
3

print(data)
[['1', 'A', 'A'], ['2', 'B', 'B'], ['3', 'C', 'C']]

Answer 2

Python List comprehension is being used here. Refer to https://www.geeksforgeeks.org/python-list-comprehension-and-slicing/ for more info on this.

data = [x for x in data if x[0].isdigit()]
print(len(data))

From the code that you have written, some modifications can be made and can be implemented without using list comprehensions also.

count =0
for i in data:
    if i[0].isdigit() == True:
        count +=1
        print(i)
print(count)

Hope this answer helps you.