python - How to delete the first line of a text file?

Question

I have been searching online, but have not found any good solution.

Here is my text file:

[54, 95, 45, -97, -51, 84, 0, 32, -55, 14, 50, 54, 68, -3, 57, 88, -1]
[24, 28, 38, 37, 9, 44, -14, 84, -40, -92, 86, 94, 95, -62, 12, -36, -12]
[-26, -67, -89, -7, 12, -20, 76, 88, -15, 38, -89, -65, -53, -84, 31, -81, -91]
[-19, -50, 16, 47, -42, -31, 75, 0, 25, -95, 75, 97, 19, 77, -2, -31, -59]
[-66, -10, 35, -39, 24, 70, 74, -45, -27, 77, -44, 86, 57, 14, -91, -26, -20]
[-63, 80, -31, 70, 100, 22, -30, 74, 44, -35, -25, -75, -39, -13, -93, 0, 1]
[63, 13, 67, 55, -56, 45, 10, 61, -14, -55, 40, 84, -59, 7, 75, -64, -25]
[7, -50, -17, -86, -43, 34, 82, 84, 49, 18, 56, -31, -19, 59, -96, 72, -40]
[-73, 34, -68, 20, 30, 1, 49, 77, -94, 2, -83, 40, 2, 20, 66, 60, -36]
[-80, -12, 93, 77, 73, -55, 24, 3, -60, 12, -41, -43, -49, 36, 6, -93, -24]
[-41, 12, -43, 42, -70, 75, -84, -83, 30, 78, -3, 51, 69, 0, 65, 60, -15]
[82, 97, -57, -96, 25, -100, 61, 13, -80, -32, 99, 60, 58, -58, -45, -58, -53]
[-90, -34, 80, 95, -12, -34, 71, -83, 46, 10, -78, -40, 65, 53, -81, 40, -59]
[-80, -20, -87, -2, -54, 74, -79, 22, -20, 60, -84, -12, -40, -98, -81, -5, -35]
[33, 36, -46, 10, -77, 88, -99, -5, 19, -20, 89, 87, -47, 46, 10, 17, -67]
[-77, 73, 20, 44, 79, -14, -8, -49, 45, -49, -91, -21, 41, -13, 74, -71, -15]
[98, -99, 51, 53, 56, -78, 31, 45, 35, -36, -10, -86, 9, 94, 24, -2, -20]
[-37, 46, -77, -92, 48, -34, 75, 19, -74, -13, -100, 33, -46, 19, -60, 5, 5]
[-13, -30, -82, -70, 64, 87, 16, 67, -36, 22, -99, -92, 36, 8, 90, 48, -5]
[46, 75, -15, 24, 24, -37, -3, -45, 32, -84, -2, -16, 43, -88, 92, 27, -10]

All I want is to delete the first line (which means using the second line as the first line, not filling first line with whitespace).

Could anyone please help me with that?

Answer 1

Assuming you have enough memory to hold everything in memory:

with open('file.txt', 'r') as fin:
    data = fin.read().splitlines(True)
with open('file.txt', 'w') as fout:
    fout.writelines(data[1:])

We could get fancier, opening the file, reading and then seeking back to the beginning eliminating the second open, but really, this is probably good enough.