This is my code:

import time
import Adafruit_GPIO.I2C as Adafruit_I2C
import struct
from math import *

# Registers
OUT_X_MSB = 0x01
CTRL_REG1 = 0x2A
XYZ_DATA_CFG = 0x0E

i2c = Adafruit_I2C.Device(0x1c, 1) # Adresse accéléromètre

# Setups for calculation with configuration 2g
gPerCount = 2.0 /128

while True:
        #Recovery of data from the accelerometer
        (status,x,y,z) = i2c.readList(OUT_X_MSB, 4)

        # Formatting for calculation
        bytes = struct.pack('BBB', x, y, z)
        x, y, z = struct.unpack('bbb', bytes)

        # Calculation of the acceleration per axis as a function of the accelerometer parametrage
        x *= gPerCount
        y *= gPerCount
        z *= gPerCount


        print (x)
        print (y)
        print (z)
        time.sleep(1)

And the output is this:

-1.4375
1.4375
1.0625
-1.4375
1.4375
1.0625
-1.4375
1.4375
1.0625
-1.4375
1.4375
1.0625
-1.4375
1.4375
1.0625
-1.4375
1.4375
1.0625

I Have checked the wiring and everything and for the life of me I cannot tell what the problem is.