我的Python代码没有从.csv excel文件中提取所有信息，而且我不知道为什么

Question

I'm pretty new to the coding scene and my boss has kinda just thrown me into the fire, so I'm sorry if this is some rookie mistake, though I don't think it is.

So I'm trying to graph G versus l1 (that's not an eleven, but an L1). The data is in the file that I loaded from an excel file. The excel file is 14x250 so there are 14 arguments, each with 250 data points. The graph I put up is formatted correctly, but zero y-values show up. From what I can tell, the code is graphing the first 12 columns and leaving the last 2 columns (which contain the two sets of 'y' data) out. I cannot find where the error is and it's driving me crazy! ANY help would be greatly appreciated!

This is where I formatted the excel file and where I believe the mistake is:

header = ['l1', 'l2', 'l3', 'l4', 'l5', 'EI',
      'S', 'P_right', 'P1_0', 'P3_0',
      'w_left', 'w_right', 'G_left', 'G_right']

def loadfile(filename, skip=[], *args):
    output = []
    with open(filename, *args) as f:
        reader = csv.reader(f, quoting=csv.QUOTE_NONNUMERIC)
        for i, row in enumerate(reader):
            if not(i in skip):
                output.append(row)
    return np.array(output)

This is where I actually loaded the excel file, which is the next likely place there is a mistake:

outputs_l1 = [loadfile('FILE.csv'.format(p)) for p in p3_arr]

fig = plt.figure()
for output, col in zip(outputs_l1, colors):
    plt.plot(output[:,0], output[:,10]*1E3, col+'-')
plt.legend(['$P3 = {} Pa$'.format(p) for p in p3_arr], loc=(1.05, 0.6), fontsize=16)
for output, col in zip(outputs_l1, colors):
    plt.plot(output[:,0], output[:,11]*1E3, col+'--')
plt.ticklabel_format(axis='both', style='plain', scilimits=(-1,1))
plt.xlabel('$l1 (m)$')
plt.ylabel('G $(J / m^2) * 10^{-3}$')
plt.xlim(xmin=.2)
plt.ylim(ymax=2, ymin=0)

plt.subplots_adjust(top=0.8, bottom=0.15, right=0.7)

Answer 1

Using column names instead of numbers and combining the two plotting loops,

col = {name:i for i,name in enumerate(header)}

fig = plt.figure()
for data,color in zip(outputs_l1, colors):
    xs  = data[:, col["l1"     ]]
    wl = data[:, col["w_left" ]] * 1000.0    # column 10
    wr = data[:, col["w_right"]] * 1000.0    # column 11
    plt.plot(xs, wl, color + "-", wr, color + "--")

a possible error becomes clear: you say you want to graph G , but you are specifying w instead (cols 10 and 11, instead of cols 12 and 13).

Maybe w_left and w_data do not appear because they are outside your specified limits ( plt.ylim(ymax=2, ymin=0) )?

I think what you actually want is

fig = plt.figure()
for data,color in zip(outputs_l1, colors):
    xs  = data[:, col["l1"     ]]
    gl = data[:, col["G_left" ]] * 1000.0    # column 12
    gr = data[:, col["G_right"]] * 1000.0    # column 13
    plt.plot(xs, gl, color + "-", gr, color + "--")

---

In

def loadfile(filename, skip=[], *args):

passing [] as a default argument is a bit dangerous because changes to the default list can persist across calls to the function, causing very strange results. You should instead do

def loadfile(filename, skip=None, *args):
    skip = skip or []

except you are only using skip for membership-testing, so it would be faster as a set, so it becomes

def loadfile(filename, skip=None, *args):
    skip = set(skip or [])

---

Also,

    output = []
    with open(filename, *args) as f:
        reader = csv.reader(f, quoting=csv.QUOTE_NONNUMERIC)
        for i, row in enumerate(reader):
            if not(i in skip):
                output.append(row)
    return np.array(output)

could be shortened to

    with open(filename, *args) as f:
        cr = csv.reader(f, quoting=csv.QUOTE_NONNUMERIC)
        return np.array(row for i,row in enumerate(cr) if i not in skip)

and the result is a numpy 2d array; so

outputs_l1 = [loadfile('FILE.csv'.format(p)) for p in p3_arr]

looks like p3_arr is a list determining which data-sets you want to look at; then outputs_l1 becomes a list of 2d arrays. This is a misleading name because, looking at header , l1 is supposed to be the first column of each 2d array; thus outputs_l1 logically ought to be a 2d array containing just first-column data. I suggest renaming it to something like p_data .